St. Stephen's Cathedral (more commonly known by its German title: Stephansdom), is the mother church of the Roman Catholic Archdiocese of Vienna and the seat of the Archbishop of Vienna.
The first church on the site was Romanesque and built in the years after 1137 but burnt down in 1193. It was re-built in early Gothic style; that church also burnt down in 1258.
Today′s cathedral was built between 1359 when Rudolf IV laid the foundation stone for a new cathedral that was meant to emphasise the role of Vienna as a capital, and the early 20th century, when some of the choirs and chapels were finished. It now appears in late Gothic and typically Germanic style.
On the west front, to the left and right of the Giant's Door, are the two Roman Towers, or Heidentürme, that each stand at approximately 65 metres (213 ft) tall. The name for the towers derives from the fact that they were constructed from the rubble of old structures built by the Romans (German Heiden meaning heathens or pagans) during their occupation of the area. Square at the base and octagonal above the roofline, the Heidentürme originally housed bells; those in the south tower were lost during World War II, but the north tower remains an operational bell tower. The romanesque Roman Towers, together with the Giant's Door, are the oldest parts of the church.
The glory of St. Stephen's Cathedral is its ornately patterned, richly coloured roof, 111 metres (364 ft) long, and covered by 230,000 glazed tiles. Above the choir on the south side of the building the tiles form a mosaic of the double-headed eagle that is symbolic of the empire ruled from Vienna by the Habsburg dynasty. On the north side the coats of arms of the City of Vienna and of the Republic of Austria are depicted. In 1945, fire caused by World War II damage to nearby buildings leapt to the north tower of the cathedral and destroyed the wooden framework of the roof. Replicating the original bracing for so large a roof (it rises 38 metres above the floor) would have been cost prohibitive, so over 600 metric tons of steel bracing were used instead. The roof is so steep that it is sufficiently cleaned by the rain alone and is seldom covered by snow.