Around AD 1100: The Norman round church shaped by the Crusades

The Holy Sepulchre, a round church in Northampton, England, is a remarkable example of Norman architecture. Dating back to around AD 1100, the church is believed to be built by William the Conqueror's half-brother Robert, Count of Mortain. After his return from the First Crusade, Simon de Senlis, Earl of Northampton, might have been inspired by the Church of the Holy Sepulchre in Jerusalem, a church he would have seen on a pilgrimage. However, the evidence suggests that Simon de Senlis built the Northampton Castle and town wall instead of the Holy Sepulchre in Northampton.

The original church had a round nave of 8 columns, but it's not clear if an ambulatory ran round the perimeter. A North aisle was added circa 1180, and a second North aisle was added circa 1275. During the early 15th century, a South aisle was built and the triforium was replaced by a clerestory. The Holy Sepulchre in Northampton is one of four medieval round churches still in use in England. The others are Holy Sepulchre in Cambridge, Temple Church in London, and St John the Baptist in Little Maplestead, Essex.

Sources: Wikipedia, OpenStreetMap, Wikidata, Wikimedia Commons