|Gylian Embassy, Vichenza||Cacertian Embassy, Mişeyáke|
The relations between Gylias and Cacerta officially began in 1958, with the independence of Gylias, while their history goes back to the ancient period. Relations between the two countries have generally been stable, and have progressed from their cordial establishment to close ties — characterised as a special relationship within Gylian foreign policy.
Gylias and Cacerta have developed active economic, political, and cultural relationships beginning in the late 20th century. Diplomatic relations have at times stalled due to foreign policy disagreements or domestic issues, but by the 21st century the two countries mutually regarded each other as close allies and partners.
Bilateral relations today are mainly focused on social and economic issues, and both countries benefit from cooperation in various fields, such as culture, economics, and science.
The first contacts between the Gylic peoples and Cacertians date to the Sabrian Empire. The Sabrians primarily obtained a foothold on the eastern coast, where the Zinerans and Varans paid tribute to the Sabrians while simultaneously remaining part of the Liúşai League.
Sabria became a significant trading partner for the League, and the loss of its trading networks and disintegration following the Sabrian Wars had an economic impact. However, mutual contacts continued, and reached a new peak after the emergence of the Padovan Empire.
Cacerta became one of the League's significant trading partners, alongside Kirisaki. Trade allowed the Gylic states access to new technologies and developments in shipbuilding. Early exposure to Cacertian culture helped spur the development of Gylic literature and theatre, while the earliest interactions between Concordianism and Sofianism are attested during this period.
Cordial relations between Cacertian and Gylic states endured during the early Centuries War Period, during which the League sought to remain neutral and not back any sides. The appearance of feudalism in Cacerta meant that many early Cacertian immigrants who settled in the Gylic states were dispossessed farmers.
Xevden's conquest of the Gylic states, completed in 1704, triggered a long period of hostile relations after Cacerta was unified in 1871. Although bilateral relations ceased to exist in practice, the Gylic and non-Xevdenite populations retained a positive image of Cacerta, and it was a significant destination for refugees and migrants.
The Xevdenite state, which entered into irreversible decline in the early 19th century and lurched from crisis to crisis henceforth, was a suitable target for the expansionist efforts of the Cacertian Empire under Empress Elliana.
Cacerta and Xevden fought a brief war in 1904–1908, which ended with a Cacertian victory. Many Gylians forced into service in the Xevdenite military deserted to the Cacertian side. After the war, Cacerta annexed Iárus Island and part of the Xevdenite north-east, as Alscia Province.
Gylians residing in Alscia benefited greatly from Cacertian rule, experiencing a period of rapid economic development and a restoration of democratic government that had been usurped by Xevden. The governor of Alscia, Donatella Rossetti, amassed significant political power, becoming one of the first Gylian women to distinguish herself in public service, and committed Alscia to the fight against Xevdenite oppression, making it into a base from which Gylian radical movements and literature spread through Xevden.
The dissolution of the Cacertian Empire coincided with the collapse of the Xevdenite kingdom — Alscia became independent a year into the Liberation War and joined the Free Territories, their industries and shipyards proving crucial in the victory of the People's Army.
While Cacerta remained neutral during the conflict, the leftist governments in office engendered sympathy among the public for the anarcho-communist PA, with Cacertian volunteers being part of the International Brigades. The journalist Luisa Braglia became famous for her sympathetic coverage of the Free Territories and Gylian anarchism.
Gylias' independence in 1958 was met with suspicion by many Tyranian states, owing to the anarchist ideology of the victors. The new Prime Minister, Darnan Cyras, had been educated in Cacerta and lived there for many years. Bilateral diplomatic ties were established, and embassies were opened in both countries.
Gylian foreign policy was characterised by "popular diplomacy", seeking to encourage regular interaction between Gylian and Cacertian people as a way to strengthen relations.
Cultural exchange initiatives assumed an important role in bilateral relations. Measures included building cooperation between Gylian and Cacertian broadcasters and performing ensembles in fields such as opera, classical music, and theatre, encouragement of bilateral tourism, and regular youth and student exchange initiatives.
Cacerta joined the Common Sphere in 1967, which provided additional benefits to bilateral trade. The Gylian Self-Defense Forces and Cacertian Armed Forces entered into a military supply agreement in the 1970s.
Relations between the two countries cooled during the 1980s, part of an overall trend towards diplomatic isolation under the Aén Ďanez government. Close relations were restored during the 1990s, under the Mathilde Vieira government. Cooperation between Cacerta and Gylias has since increased in various fields, including economic issues, support for human rights and democracy in foreign policy, scientific research, defense, and renewable energy.
"The Year of Cacerta in Gylias" was first organised in 1998, to mark 40 years of official relations, with its counterpart "The Year of Gylias in Cacerta" taking place the following year. Co-productions by the Gynbris and CBC have increased in number since the 2000s, and a similar trend of closer cooperation has been identified between the Gylian and Cacertian animation industries.
In 2008, the two countries jointly commemorated the 100th anniversary of Alscia's establishment.
Queen Anelyn I undertook the first Cacertian state visit to Gylias in May 2013. Her visit was well-received. She addressed the Gylian Parliament on 31 May 2013. The personal friendship between Anelyn and Prime Minister Toni Vallas is credited by many observers with representing a peak in Gylias-Cacerta relations.