Berthold II (c. 1050 – 12 April 1111), also known as Berchtold II, was the Duke of Swabia from 1092 to 1098.After he conceded the Duchy of Swabia to the Staufer in 1098, the title of "Duke of Zähringen" was created for him, in use from c. 1100 and continued by his successors until 1218. Berthold, beginning in 1090, extended his power into the Breisgau so that the Zähringer territory extracted itself from the influence of the Swabian duke. In 1091, he abandoned Zähringen castle as his main residence, in favour of the newly built Freiburg Castle.