The Cathedral Church of Saint German was built in 1879–84. The Patron of the Cathedral, St German of Man, was a Celtic missionary and holy man who lived from about 410 to 474.
The original cathedral of St German was inside the walls of Peel Castle and was built sometime in the 12th century when St Patrick's Isle was in the possession of Norse kings. At that time the church followed the Sarum Rite, prevalent throughout much of the British Isles. Around 1333 the Lords of Man refortified St Patrick’s Island and occupied the church as a fortress. In 1392 William Le Scroop repaired the Cathedral.
The building fell into ruin in the 18th century. After a considerable period of debate over who owned the ruins and site, it was decided not to rebuild that cathedral. The present building was constructed in 1879–84 to replace St Peter's Church in Peel's market place. In 1895, the bishop consecrated his chapel at the bishop's palace as pro-cathedral and instituted a chapter of canons with himself as Dean. That arrangement (bishop as dean) persisted even after the consecration of the new cathedral.
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.