Its rebuilding was taken over by Wren in 1671 and mostly completed by 1684.
That building had nine bays incorporating a tower at the west end but, between 1762 and 1768, the two westernmost bays were demolished to allow for a widened pedestrian route through the base of the tower onto old London Bridge; the tower's lowest storey thus became a porch, and still is.
There have been many changes to the building since 1684. Finally, in 1924, the spacious, severe interior was restored in a neo-Baroque style to reflect its Anglo Catholic congregation.
The high altar is backed by a two storey reredos and flanked by two side chapels. On the north wall is a Russian icon, while in the south aisle stands a statue of St Magnus, holding a model of the church.
St Magnus also contains an extraordinary four metre long scale model of old London Bridge, with which it has been so intimately connected throughout the years.
Enjoy a virtual tour here: