St Martin's Tower, popularly called "Carfax Tower", is on the northwest corner of Carfax. It is all that remains of the 12th-century St Martin's Church and is now owned by Oxford City Council. It was the official City Church of Oxford, where the Mayor and Corporation were expected to worship, between about 1122 and 1896, when the main part of the church was demolished to make more room for road traffic and All Saints' Church in the High Street became the City Church for 75 years. All Saints then became the library of Lincoln College, and St Michael at the North Gate became the City Church.