The early medieval Parish church of St. Martin Busskirch with its cemetery rests on the remains of a Roman building (1st to 4th century AD). It is one of the oldest churches around the Lake Zürich. Even the citizens of Rapperswil had to attend services in Busskirch until Count Rudolf II of Rapperswil built his own church and a chapel next to Rapperswil Castle in 1253.
In 1351 St. Martin Busskirch was incorporated by the monastery (until 1838). In co-operation with Jona the settlement formed an Allmendgenossenschaft (farmer's association), reigned by the Counts of Rapperswil, latter by the city of Rapperswil. In 1253 the parish churches of Rapperswil and Jona were established: St. Martin Busskirch lost its former importance and was in 1945 integrated in the Roman Catholic parish Rapperswil.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.