The younger line ruled the comital lands of Gorizia and Lienz until its extinction in 1500, whereafter the estates were finally acquired by the Austrian House of Habsburg.

He campaigned the adjacent Duchy of Carinthia but was defeated by the troops of Duke Bernhard von Spanheim and his son Archbishop Philip of Salzburg at Greifenburg in 1252.

The Council of Ten strived for the adjacent "inner county" lands around Gorizia up to the Venetian Stato da Màr territories in Istria.

His son, the last count Leonhard, died in 1500 and despite claims raised by Venice, according to a contract of inheritance and the active support of the Gorizia governor Virgil von Graben[2] the county fell to the Habsburg emperor Maximilian I.

Its territory included the Isonzo Valley down to Aquileia, the area of Cormons and Duino, and the former Venetian fortress of Gradisca, which was conquered by Imperial troops in 1511.