In 1205 in Daugavgriva (Dünamünde), a Cistercian abbey was founded by Theodoric von Treiden, the first Christian monastery in Livonia. It became the intellectual background of the region, and the first bishops of Dorpat, Ösel–Wiek and Sēlpils were previously just abbots of Dünamünde. The local Cistercians also participated in the process of making the most important decisions, regarding the formation of Livonian Church and administrative structures and the establishment of the Order of Livonian Brothers of the Sword. Their financial back-up was the salaries in the conquered areas and numerous lands located safely in Germany. The monastery was not stopped even by the invasion of the Curonians in 1228, when the entire convent was murdered. The abbey was quickly rebuilt, so that already in 1268 it defended itself against another attack.
As the monastery was located on the river Daugava and was able to control all its trade and transport to rich cities such as Polotsk, Vitebsk or Riga, Dünamünde became the object of interest of the Teutonic Order. In 1305, wanting to tame Riga and its archbishop, the Teutonic Knights forced the monks to sell the monastery to the Teutonic Order, which rebuilt it into the cammandry castle. Its first commander was the order knight Heinrich Hecht. The Cistercians moved to Padise, and Dyjamund became the object of disputes between the Order and Riga, inflamed by the Teutonic attempts to block the navigability of the river by dragging the chain from the castle to the other shore. For this reason it was repeatedly conquered by burghers, for the first time in 1329. The heaviest of battles took place in the early 80s of the fifteenth century, the siege lasted four weeks and ended with a total demolition of the castle. It was rebuilt by the Livonian landmaster Wolter von Plettenberg and remained in the hands of the Teutonic Knights until it was taken by Poles in 1561.
In 1582, king Stefan Batory ordered to further strengthen the castle, which, however, in 1608 was captured by the Swedes. A year later, the Lithuanian hetman Jan Chodkiewicz recaptured it. Successful defense was carried out by the Poles in 1617, but a few years later, together with Riga and the majority of northern Livonia, it came under Swedish rule. In 1624, they erected an early modern bastion fortress on the site of a ruined medieval castle.
It is not known how the original Cistercian monastery looked like, it can only be supposed that it had defensive features, since in 1228 and 1268 it was besieged. The castle from the Teutonic era had a regular shape, similar to the form of the conventual castle. It had a square main tower in the south – west corner, which was the oldest element of the castle and three corner defensive towers. A chapel was added to the tower on the eastern side. Then buildings were erected along the western and northern curtain walls and two shorter annexes to the eastern wall. The main gate was on the south-west side. Later, three corner towers were added to the outer belt of fortifications.
From the original Cistercian monastery to this day even foundations have not been preserved. The oldest visible element are earth defensive ramparts built during the times of king Stefan Batory, although it is possible that they partially come from the Teutonic Knights era.
Borowski T, Miasta, zamki i klasztory, Inflanty, Warszawa 2010.