Sineus and Truvor were the brothers of Rurik, a chieftain of the Varangian Rus tribe considered to be the founder of the Rurik dynasty, which ruled the Kievan Rus. According to the Russian Primary Chronicle, the town of Izborsk was the seat of Truvor from 862 to 864. Although his burial mound is still shown to occasional tourists, archaeological excavations of long barrows abounding in the vicinity did not reveal the presence of the Varangian settlement at the site, which indicates that Izborsk was an important centre of the early Krivichs.
Truvor's gorodishche is a settlement about half a kilometer north from the fortress that came about in the late 7th and early 8th century, and proceeded to grow twice in size in the 10th and 11th centuries. It was the predecessor of the Izborsk Fortress, protected by an oakwood wall which was later upgraded to stone, 3 meters in height by 3 meters in width in the 12th century. Though Truvor's gorodishche is mostly destroyed, a small part of the wall remains today.
References:Trenčín Castle is relatively large renovated castle, towering on a steep limestone cliff directly above the city of Trenčín. It is a dominant feature not only of Trenčín, but also of the entire Považie region. The castle is a national monument.
History of the castle cliff dates back to the Roman Empire, what is proved by the inscription on the castle cliff proclaiming the victory of Roman legion against Germans in the year 179.
Today’s castle was probably built on the hill-fort. The first proven building on the hill was the Great Moravian rotunda from the 9th century and later there was a stone residential tower, which served to protect the Kingdom of Hungary and the western border. In the late 13th century the castle became a property of Palatine Matúš Csák, who became Mr. of Váh and Tatras.
Matúš Csák of Trenčín built a tower, still known as Matthew’s, which is a dominant determinant of the whole building.