Here the Glan reaches the Central Carinthian Zollfeld plain and flows southwards to Maria Saal and the state capital Klagenfurt am Wörthersee.

He was succeeded by his brother Duke Hermann II of Carinthia, who became Vogt protector of the church in 1176 and subsequently the Sponheimer made the estates of St. Veit their permanent residence and capital of the Carinthian duchy, which it remained until 1518.

Herman's son Bernhard von Spanheim (d. 1256) had the ducal castle and fortifications built, and granted St. Veit town privileges 1224.

St. Veit also may have been the domicile of Heinrich von dem Türlin where he wrote his Middle High German Diu Crône poem.

His granddaughter Countess Margaret in 1335 finally lost Carinthia to Duke Rudolf IV of Austria from the House of Habsburg, whereafter it was incorporated into the dynasty's Inner Austrian lands and ruled by stadtholders.

In 1362 Rudolf granted the St. Veit citizens the permission to hold the annual Wiesenmarkt fair, which is arranged up to today as one of the oldest festivals in Central Europe.