The site used to be part of Blegedam Common, one of the commons which used to surround Copenhagen when it was a fortified city. The square was originally a cattle market for the livestock which grazed on Blegedam Common as well as the adjoining Northern and Eastern Commons. It takes its name from St. John's Church which was completed on a site just east of the square in 1861. As the surrounding area was redeveloped into a dense residential neighbourhood and traffic increased, the square was reduced to a large road junction