Sanga-durga
A Sanga-durga (lit. community-fortress) is a type of fortress constructed in Satria from arrival of the First Phuli Empire in the region in XX BC to the fall of the Sangma Empire in 1447. In contrast to the Dawpruva of neighbouring Tusing and more in common with, most Sanga-durga were originally established as monasteries under the First Phuli Empire to collect taxes and tribute, usually on the sites of pre-existing fortresses and citadels of the various conquered Bashurat River Kingdoms.
Sanga-durga played a vital role in the control and administration of the distant but populous Bashurat Valley under the First Phuli Empire, as well as the spread of Satyism into the region. The Siege of Cheel ka Teela, one of the largest sanga-durga, in 194 BC marked the end of the War of Vajramitra, the last notable attempt by the native Satrian aristocracy to overthrow the First Phuli Empire. During the fall of the First Phuli Empire and the spread of Badi into the Bashurat Valley, the administrative bureaucracy of the sanga-durga was carried over largely intact into the Sangma Dynasty. During the First Sangma Interregnum and Second Sangma Interregnum Sangma interregnums and the Sangma Middle Period from 116 AD to 229 AD, the sanga-durga largely lost their civil and administrative functions as various factions sought to establish their own systems of local governance, usually within the cities themselves and separated from the monk-scholars and their perceived loyalty to the sanga-durga over the faction they worked for.
Sanga-durga remained important fortified locations, and many sangma-durga were besieged during the Interregnums by groups seeking to occupy the well-fortified and strategically located fortresses. Although some sangma-durga surrendered peacefully and shared the fortress with soldiers for the conflicts, others refused, concerned about the implications for their independence. These sanga-durga that resisted founded the tradition of the Sipahi, warrior-monks who would defend their sanga-durga's independence and autonomy. This period also had the mass-collapse of communication between the sanga-durgas, resulting in each sanga-durga having its own minor variation on the practice of Pracyavada.
After the end of the Interregnums, many sanga-durga resumed their administrative roles while others remained autonomous as purely religiously focused establishments. After the fall of the Sangma Empire and the loss of their administrative roles to local Irfanic rulers in some areas and independent warlords in others, the sanga-durga remained purely religious establishments where followers of Pracyavada would gather to assist one another in achieving Tula. The Sipahi tradition would grow, as some rulers attempted to take control of sanga-durga within their territory directly. Many sanga-durga were de-established by colonial authorities, fearing them as potential nexuses of colonial revolt, while the Rajadom of Ajahadya established their autonomy from the state in the Sanga-durga Act of 1891.
Many sanga-durga still exist today, with the largest and most famous being the Cheel ka Teela which is approximately 40 miles northeast of Banabadura.