In 1211 the hill-fort of the Estonians in Viljandi was besieged by a joint army of Germans, Latvians, and Livs. The Livonian Sword Brethren captured the hill-fort in August 1223 from a contingent of Russians, who joined forces with the insurgent Estonians. The following year the Grand Master Volquin led the construction of the castle at the site of the former hill-fort. The Viljandi (Fellin) castle was one of the largest in the Baltic region. It was a major fortification of the Livonian Order and was appointed a commander from 1248. The fortress was continually rebuilt and modernized over the next two-hundred years.