The modern village of Altnau may be first mentioned in 787 as "Althinouva". In the 8th Century the Abbey of St. Gall owned most of the land in Altnau. In 1155, Emperor Friedrich Barbarossa confirmed that the Cathedral of Constance owned the church and church yard in the village. The vogt right over the church's farms belonged to the Freiherr of Altenklingen after 1300. During the Late Middle Ages, this right was given to several noble families from Constance; 1378 Schwarz, 1430 Tettikofen, 1468 Mangolte, and from 1471 until 1798 the city of Constance directly controlled the farms. In 1454 the villagers were represented in the Appenzell "Landrecht", but following complaints from Constance they were forced to give up their membership. The rights of the village are first listed in the "Gerichtsoffnung" of 1468.