Battle of the Koryal Plain

Battle of the Koryal Plain
Part of the Invasion of Ruvelka
Ruvelkan infantry fighting in Kaposvár.
Date 10 April - 2 May 1934 Location Nortern Ruvelka Result Syaran victory
Belligerents
Republic of Syara	Ruvelka
Commanders and leaders
Kostadin Zhelyaskov Galin Miroslavov Tsvetkov Zdravko Merakovski	Veronika Mezei Dominik Máté Vicken Kostoyan
Units involved
Army Group Alpha First Army Ninth Army	Military District of Kunhegyes 1st Northern Front
Strength
360,000 troops 1,244 tanks 1,355 aircraft 2,340 artillery pieces	550,000 troops 320 armored vehicles 400 aircraft 1,200 artillery pieces
Casualties and losses
7,450 killed 22,000 wounded 209 tanks destroyed 128 aircraft lost	21,000 killed 63,000 wounded 350,000 captured

The Battle of the Koryal Plain was the largest battle of the 1934 Invasion of Ruvelka, fought between 10 April and 2 May. The battle occurred as the Syaran Army Group Alpha, spearheaded by the First and Ninth Armies, pushed into the Koryal Plain with the ultimate goal of capturing the Ruvelkan port of Mátészalka. They were opposed by forces of the Ruvelkan Imperial Army of the 1st Northern Front and the Military District of Kunhegyes.

The battle occured over the course of several weeks as the Syarans advanced in the face of repeated Ruvelkan counter-attacks. Despite stiff Ruvelkan resistance, the Imperial Army was unable to prevent the fall of the cites of Kaposvár and Kunhegyes. By the end of April the Syarans had encircled the bulk of Ruvelkan forces of the 1st Northern Front, which surrendered on 2 May. The subsequent capture of Mátészalka, coupled with the entry of Arkoenn into the war, effectively ended any chance of a Ruvelkan defensive strategy.

Background

Northern Ruvelka, which straddles the Koryal Plain, features some of the flattest terrain in Ruvelka while also posesses significant deposits of petroleum. This made it a major focus for the Syarans for Operation Sarissa, the invasion of Ruvelka, which fell to Army Group Alpha. The Ruvelkan plan of defense as envisioned by Paloma Keresztes in her time as Chief of the General Staff called for avoiding a protracted attempt to hold the border with Syara itself in favor of conducting a phased withdrawal to a series of defenisive lives further east, giving time to establish more instrength positions along the Kurilla Mountain Range.

Executing this plan proved difficult for the Imperial Army, which lacked motorization and a national infrastructure that was still recovering the Ruvelkan Civil War. The Army of the Syaran Republic initially had made only limited progress into Ruvelka, but by 10 April the Syarans had begun advancing across the border and engaging elements of the Ruvelkan Army. The Syaran effort was led by Army Group Alpha under the command of Field Marshal Kostadin Zhelyaskov. Army Group Alpha's two spearheads were First Army under Colonel General Galin Tsvetkov and Ninth Army under Zdravko Merakovski. Tsvetkov commanded four infantry divisions in addition to five armored and mechanized divisions, while Merakovski controlled seven infantry divisions, two cavalry divisions, and one cavalry brigade. The Syarans had significant advantages in tanks, artillery, and aircraft despite being numerically inferior. In addition, despite their generally slow moving doctrine, most Syaran divisions were motorized and thus could move and react faster than their Ruvelkan counterparts.

Defending northern Ruvelka were forces under the Military District of Kunhegyes, commanded by General Veronika Mezei. Additional forces existed under the 1st Northern Front, an ad hoc formation of reservists and hastily mobilized conscripts under the command of General Dominik Máté. Additional forces consisted of four regiments of Imperial Fusiliers led by Major General Vicken Kostoyan. The Kunhegyes Military District consisted of four infantry divisions, one of Ruvelka's three armored divisions, and approximately 200 aircraft. The Northern Front on paper should have fielded an additional 12 infantry divisions and three more cavalry divisions, but these were still mobilizing by the time the fighting started. The Imperial Fusilier Regiments were in theory the best prepared of the Ruvelkan forces, but they lacked anti-tank weaponry and supplies. All together the Ruvelkans fielded somewhere around 550,000 troops, but many of them were recent conscripts organized into regiments with little more than rifles, a few machineguns, and mortars. Anti-tank weaponry, anti-aircraft guns, and heavy weapons were in short supply all around.

The Koryal Plains would be the largest tank battle of the invasion with 1,500 tanks taking part, albiet a clear majority of them on the Syaran side. Despite the numbers neither side was experienced in armored warfare. The Ruvelkans were largely unfamilar with any large scale manuevers and during the invasion remained uncertain as to how to best employ what armored forces they had. The Syarans had a primitive understanding of armored warfare; having rejected the idea of the breakthrough entirely, the Syarans saw their armored units as simply heavy divisions meant to batter the enemy into submission and did not employ them as highly mobile independent formations.

Course of the battle

The Koryal Plain is home to several major urban areas, chief among them Kaposvar and Kunhegyes. The plain extends eastward until the foothills of the Kurillas near Soltvadkert, after which the terrain becomes more rugged the closer one draws to Mátészalka. The Koryal Plain resides largely within the Kunhegyes District, and thus during the war fell under the protection of the Kunhegyes military district command of General Veronika Mezei. Shortly after hostilities had started the military district forces were reinforced with the hastily raised 1st Northern Front under General Dominik Máté.

For the first six days of the war the Syarans of Army Group Alpha made little progress into Ruvelka, focusing instead on securing river crossing on the Granika River which served as the border for most of the Kunhegyes District with Syara. On 10 April the Syarans finally began their major push into the Koryal Plain with two spearheads, First Army under Colonel General Galin Miroslavov Tsvetkov and Ninth Army under Colonel General Zdravko Merakovski. The Syaran plan was for First Army to capture Kaposvár and Ninth Army to capture Kunhegyes, after which both armies would push further east before connecting at Soltvadkert to encircle and annihilate the forces between them. The city of Sarud, which sits roughly half-way between Kaposvár and Kunhegyes, was to be avoided initially and captured by follow up forces from the Second Army.

Mezei recognized Ruvelka's long term defensive strategy involved successive defensive lines stretching back to the Kurillas, exploiting Ruvelka's terrain as a defense-in-depth rather than concentrating all available forces near the border. Rather than commit to early battle, Mezei ordered most of the District's military forces to fall back to the "Sarud Line", protecting the railroads and highways between Kaposvár and Kunhegyes. To delay the Syaran advance Mezei ordered Major General Vicken Kostoyan's Fusiliers to conduct a delaying action west of the Sarud Line to hold up the Syaran advance as long as possible to allow the 1st Northern Front time to full mobilize and prepare for combat.

Mezei drew up her four infantry divisions (11th, 21st, 24th, and 30th) along her defensive line with the 2nd Armored Division formed an operational reserve meant to check the advance of any potential Syaran breakthrough. Such a breakthrough however was not in accordance with Syaran army doctrine, and as a result on 10 April the Syarans of 1st Army fell upon the Ruvelkan lines with sustained barrages from Syaran 105mm and 155mm artillery followed by direct assaults by Syaran armored and mechanized forces from 3rd Corps. At the same time, the Syaran 9th Army struck Ruvelkan defenses between Sarud and Kunhegyes with six infantry divisions. Under devastating bombardment from Syaran artillery that Ruvelkan batteries could not match, Mezei ordered her forces to fall back on 11 April after less than 24 hours of fighting.

Kaposvár and Kunhegyes

Due to the slow rate of the Syaran advance, the Ruvelkans were able to reconstitute themselves in good order closer to Kaposvár and Kunhegyes, which the Syarans advanced to on the 12th. The Syarans pressed their attack the next day on the 13th. Ruvelkan forces around Kaposvár were forced to coalesce around the city and were unable to prevent the Syaran 4th Corps from seizing Balaskáta, which cut off the Ruvelkans from their rain link south. Having suspected the effort, General Mezei ordered the 2nd Armored Division to counterattack and retake Balaskáta. Armed with a mixture of 30M Light Tanks and 33M Medium Tanks, the 2nd Armored clashed with 4th Corps' 1st Armored Division south of Balaskáta around noon. Armed with Thaumas heavy tanks, the Syaran 1st Armored successfully repelled the Ruvelkan attack but the continuously slow Syaran pace of operations meant the Ruvelkan 2nd Armored was able to retire in good order. The engagement had cost the Ruvelkans 23 tanks in exchange for 8 Syaran chassis losses.

In the south Merakovski's infantry-heavy 9th Army struck Ruvelkan forces around Kunhegyes. Overall command of the 21st and 30th Infantry Division and the Fusiliers fell to General Cintia Mezei, younger sister of Kunhegyes District commander Genearl Veronika Mezei. The younger Mezei hoped to exploit the lack of armor in the Syaran 9th Army to her advantage but had only a handful of tanks under her command. When the Syarans threatened the rail hub at Nisnța, just north of Kunhegyes, Mezei led her handful of 33Ms in a counterattack against the Syaran 2nd Corps, which succeeded in temporarily forcing the withdrawal of the 4th Light Cavalry Division. On the south side the Syaran 41st Corps succeeded in breaking through Ruvelkan defenses and seizing Zvona, cutting off Kunhegyes from rail connections south.

Recognizing that her efforts to protect both cities were beginning to fail, District Commander Mezei ordered her forces to withdraw further east, linking up with advancing elements of the still mobilizing 1st Northern Front. Front Commander Máté had in theory 12 divisions under his command, but most were still under-strength and under-armed. With reinforcements still streaming in from staging areas across northern Ruvelka, the Ruvelkan forces enjoyed a numerical advantage but were outclassed in firepower and mechanization. General Máté had organized his forces into four field armies of three divisions each, designated the 15th Army under General Mihaly Vass, the 17th Army under General Florian Sandor, the 23rd Army under Marta Dgebuadze, and the 25th Army under Ioseb Gogolidze. The combined Ruvelkan forces, on paper, amounted to over half a million troops, but had just 320 armored vehicles between them against more than 1,200 Syaran tanks.

Mezei wanted to employ the 1st Northern Front's armies as a counter-attacking force while the Syarans were still attempting to capture Kaposvár and Kunhegyes and ordered Kostoyan's Fusiliers to conduct a partial scorched earth policy to deny the Syarans immediate usage of north-west Ruvelka's rail network and roadways, delaying their advance long enough for Máté's forces to take up positions. Thanks to aerial reconnaissance provided by the Syaran Army Air Corps, Army Group Alpha's commander Field Marshal Zhelyaskov was made away of Ruvelkan troop movements and ordered the aircraft under his command to conduct strikes against the advancing forces of the Northern Front. Between 11-15 April more than 350 Delphyne medium bombers and Gerana fighter/bombers struck Ruvelkan columns as they advanced west to meet the Syarans. The Ruvelkan Imperial Air Force attempted to clear the skies of Syaran bombers, but lacked modern fighters to contest the Syarans. By 18 April none of the airfields in the Koryal Plain were still available for usage to the RIAF due to Syaran bombings, further weakening Ruvelka's already strained air force.

Ruvelkan counter-attack

By 16 May the April the Syarans had captured Kaposvár and Kunhegyes and were advancing west. Recognizing the Syaran pincer effort as the two Syaran armies advanced, Mezei ordered the Northern Front to take up blocking positions while what remained of the District forces and what reserves Máté had attempted to outflank the Syaran armies. On 17 April Vass's 15th Army struck Tsvetkov's First Army near Dzerkhove while the 23rd Army under Dgebuadze struck the Syaran southern flank close to Kirotrov. Further south Sandor's 17th Army met Merakovski's Ninth Army at Biatorklós while Gogolidze's 25th Army hit the left wing of the Ninth Army near Białyskie. Kostoyan's Fusiliers meanwhile attempted to conduct infiltration operations into the Syaran rear echelon to harass the extensive logistical trail of Army Group Alpha.

The Ruvelkan plan of attack was fundamentally sound but the Ruvelkan formations lacked the mass and firepower to carry it out. Vass's 15th Army found itself facing the Syaran 3rd Corps consisting of the 1st Motorized, 3rd Armored Cavalry, 2nd Mechanized, and 2nd Sibko Infantry division and was soon overwhelmed by the volume of Syaran armor that the 15th Army's single battalion of 30M Light Tanks simply weren't capable of handling. The Syarans of 3rd Corps quickly rolled over the 15th Army's attack and by the evening the Ruvelkans were routing and Dzerkhove fell into Syaran hands.

Further south the 23rd Army initially enjoyed some minor success against the Syaran 32nd Infantry Division which was screening the right flank of the Syaran advance. But by midday the Ruvelkans found themselves facing the rest of 4th Corps, which included the 1st Armored Division and the 15th Motorized Division. Having recognized they were facing the tank heavy forces of the First Army, Máté had chosen to deploy his single battalion of Kristóf Barta Heavy Tanks; the only ones available to the Northern Front. Commanded by Major Keti Melkadze, the 32 KBs were the most powerful offensive weapon the Ruvelkans fielded during the invasion and initially proved successful, as Melkadze noted in her memoirs:

We guided the [117th Infantry Regiment] off the road to Kirotrov when the Syarans opened fire from the tree line. Their 47mm guns ricocheted off our armor and once we realized they didn't have any 75mm guns, the only ones we really had to worry about, I ordered the battalion to advance. Once the Syarans realized that their guns couldn't penetrate our armor, they bolted like rabbits. It was actually to our disadvantage; by the time I had sighted my machine guns scope at them, they were already fleeing beyond our range. We captured six guns and a few machine guns and I ordered the infantry to follow us as we tried to pursue the Syarans.

However as the attack continued the 1st Armored slammed into the 23rd Army. While Syaran tank formations were inflexible and slow moving, they consisted of over 400 tanks, more vehicles than the entire Northern Front commanded. 4th Corps commander, Lt. General Bogdan Razvigorov, launched his counter-stroke head on with the 1st Armored supported by the 15th Motorized, which met the Ruvelkans north of Kirotrov. Melkadze's battalion initially encountered the Syaran advance guard of Amycus light tanks which her forces destroyed, but soon after began encountering heavier Elatus and Thaumas tanks backed up by Syaran 75 mm anti-tank guns. The Ruvelkan infantry attempted to assist in countering the Syaran armored attack, but Keresztes PTP-28 anti-tank rifles were in short supply and of limited effectiveness against some of the heavier Syaran chassis.

Not long after the fighting began Syaran 105mm and 155mm artillery began falling on the Ruvelkan lines, further throwing off the Ruvelkan effort. After just a few hours of fighting Melkadze had to order her battalion to fall back after losing nearly half of her KBs, and not long after General Dgebuadze was forced to order the 23rd Army to fall back. Once again the slow pace of the Syaran battle rhythm allowed the Ruvelkans to retire in fairly good order, even Melkadze's slow moving battalion. Nevertheless, the attack had failed and Ruvelkan forces in the north were once again in retreat.

Having learned of the impending attack against his Ninth Army, Colonel General Zdravko Merakovski hastily drew up a defensive posture on his forward and north flanks. In the north near Białyskie Merakovski 2nd Corps commanding officer Lt. General Radoslav Nikolaiev Hadjiivanov to dig in the 4th Sibko Infantry Division along a wide front with the 5th Motorized reinforcing their position. Merakovski then rapidly shifted the 3rd Light Cavalry Brigade from the 41st Corps in the south to 2nd Corps location. In the east Merakovski ordered 11th Corps with its three infantry divisions to assume defensive positions while the 1st Light Cavalry prepared to function as an operational reserve to deal with any potential Ruvelkan breakthrough.

The Ruvelkans struck in the late morning with six infantry divisions backed up by 150 tanks and armored cars. Near Białyskie Gogolidze's 25th Army struck against the 4th Sibko Division. The 4th Sibko, ethnic Hayren soldiers, successfully stood their ground despite the intensity of the Ruvelkan three-division attack, helped by rapid employment of the 5th Motorized subordinate regiments. Having momentarily stumped the Ruvelkan attack, Merakovski ordered the 4th Light Cavalry Division and the recently arrived 3rd Light Cavalry Brigade to conduct a pincer attack against the 25th Army. Pinned in place by the Hayren troops, the Ruvelkans soon found themselves under attack on both flanks of their formation, leading to the rapid collapse of their attack. Most of the Ruvelkan troops managed to escape the potential disaster thanks once more to the slow rate of Syaran advance, coupled with the Ruvelkan troops being able to handle the lighter Syaran tank forces composed of Amycus and Centaurus light tanks. Nevertheless, by 3 p.m the 25th Army had been thrown back.

At Biatorklós Sandor's 17th Army was forced to assault three dug in Syaran infantry divisions with just three divisions of his own, but unlike the Syarans without the support of heavy artillery. Despite the aid of small groups of Fusiliers from Kostoyan's Regiments, the Ruvelkans were unable to make any serious headway against 11th Corps. By late afternoon counterattacks from the 1st Light Cavalry Division began eating away at the Ruvelkans, and Sandor was forced to give the order to abandon the offensive. Merakovski's Ninth Army had simply been too prepared and too numerous for the under-armed Ruvelkans to counter, and on 18 April Mezei once again ordered all Ruvelkan forces in the Kunhegyes District to retreat.

Syaran encirclement

On 18 April Mezei radioed Imperial Headquarters in Debrecen to report on the state of her forces.

Forces under Kunhegyes District Command to include the 1st Northern Front have been unable to prevent the easterly advance of hostiles forces within the operational area of the Kunhegyes Military District. Forces under the operational control of the District Command are preparing to resume defensive efforts along the Várpaváros-Soltvadkert-Copmănești axis. District Command will initiate counter-offensive efforts once the situation has developed to allow for offensive operations.

Mezei confirmed the fall of Kaposvár and Kunhegyes and reported the supply situation of her forces before putting in a request for additional reinforcements. The Imperial General Staff responded with assurances that Ruvelka's strategic reserve was mobilizing and the Kunhegyes District Command would soon be reinforced with an additional 250,000 troops. Such mobilization efforts were in fact beyond the capability of Ruvelka's already overtaxed infrastructure to support; Arkoenn's pending entry into the war would also invalidate any Ruvelkan defensive strategy. While a few thousand reservists and hastily drawn up conscripts continued to filter into Ruvelkan staging areas in the north, the Ruvelkan struggled to make good of these; the Syaran Army Air Corps successfully denied certain transit routes available to the Ruvelkans and forced them to conduct maneuvers in small groups that were difficult to coordinate across the Koryal Plain without large numbers of radios.

For the Syarans, Field Marshal Zhelyaskov proceeded to implement a mass encirclement of the Ruvelkan forces by having First Army seize Várpaváros in the north and Ninth Army taking Copmănești in the south, after which they would link up east of the Soltvadkert River and the city of Soltvadkert itself. This would entrap the majority of the Ruvelkan forces in the District and pave the way for an advance towards Mátészalka.