Until 1891 Interlaken was known as Aarmühle. The convent of the Augustinian Canons was built around 1133 when it was mentioned as inter lacus Madon and lasted until 1528. The mill on the left bank of the Aare river was first mentioned in 1365 asAmuli, while the town on the right bank was mentioned in 1239 as villa Inderlappen.
Previously, printing, textiles, and to a smaller extent watchmaking were also of importance, but today tourism is the most significant source of income. Interlaken is one of the oldest tourist resorts in Switzerland, and it remains one of the most popular.
While some scattered neolithic flint objects, early Bronze Age swords and Roman era coins have been found near Interlaken, there is no evidence for a settlement in the area before the Middle Ages. Interlaken Abbey was built around 1133 on imperial land on the left side of the Aare river. The Abbey controlled a bridge over the river and generated an income from tolls. A village grew up around the Abbey, along with a mill (which gave the municipality its name until 1891). On the right bank of the river, Interlaken village developed. In 1279/80 the village of Unterseen developed near Interlaken village. Also near the village were the imperial castle of Weissenau and the market town of Widen. The castle and market town became the possessions of the Abbey, but fell into disrepair in the Late Middle Ages.
The Abbey was first mentioned in 1133 when Holy Roman Emperor Lothair took the Abbey under his protection. By 1247, there were also women at the Abbey. During the 13th century the Abbey's influence spread throughout the neighboring area and into the Aare and Gürbe valleys. They eventually had authority over two dozen churches along with a number of villages and farms and became the largest religious landholder in the region. During the 13th and the beginning of the 14th century the Abbey grew and prospered. However,