Around 700, the Alamanni began to migrate into Obwalden. They initially settled around the lakes while the Gallo-Romans lived up on the plateau. The Alamanni influence is noticeable around Lake Sarnen and the Kerns plateau where many place name end in -ingen, -wil and -hofen. The Gallo-Romans remained around Mt. Pilatus, the Giswilerstock and in the Melch valley. During the 8th to 11th centuries, the two populations intermarried and eventually all became Germanized. By the 9th century it was part of the Second Kingdom of Burgundy. It became part of the Holy Roman Empire following the winter military campaign of 1032-33 by Emperor Conrad II. Obwalden was given to the Counts of Lenzburg from Aargau. The counts built a castle on Landenberg hill to help them control the land.