The ruins of Illens castle stand on a rock wall above a loop of the Saane river. The castle stands on the opposite side of the river from the fortified town of Arconciel. The two castles secured both sides of a crossing (either a ford or a bridge) over the river. The castle is first mentioned between 1150 and 1276.
In 1366, the notoriously violent Count Peter of Aarberg moved into the castle and remained there for a short while. The chamberlain of Charles the Bold, Guillaume de la Baume, expanded the castle and when he left in 1470, it was an elegant and comfortable palace. During the conflicts leading up to the Burgundian Wars, Fribourg and Bernese troops stormed and damaged the building on 3 January 1475.
In 1900, it was partly repaired and expanded and served a community of Trappist monks.
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.