The House of Rapperswil respectively Counts of Rapperswil ruled the upper Zürichsee and Seedamm region around Rapperswil and parts of, as of today, Swiss cantons of St. Gallen, Glarus, Zürich and Graubünden when their influence was most extensive around the 1200s until the 1290s. They acted also as Vogt of the most influential Einsiedeln Abbey in the 12th and 13th century, and at least three abbots of Einsiedeln were members of Rapperswil family.

The Obersee is the smaller of the two parts of Zürichsee in the cantons of St. Gallen and Schwyz in Switzerland.