the church of st margaret, westminster abbey is an anglican church in westminster, london, england. it is in the grounds of westminster abbey next to the palace of westminster. it was the church of the house of commons since 1614 - 1972. it is part of the unesco world heritage site called "palace of westminster, westminster abbey and saint margaret's church". the church was first started in the 12th century by benedictine monks. the building that stands now was built between 1486 and 1523. the church is dedicated to margaret of antioch.