Perchtoldsdorf Castle probably was laid out before 1000 AD, part of a chain of fortifications along the eastern rim of the Vienna Woods. One Lord Heinricus de Pertoldesdorf was mentioned in an 1138 deed, during the Babenberg rule. Their Perchtoldsdorf vassals continued to rule from the castle even when the Babenberg dynasty became extinct in 1246.
The conflict between the Habsburg emperor Frederick III and his younger brother Archduke Albert VI of Austria started an unstable period in the region. In 1446, many homes in the town were burned during the invasion of the Hungarian regent John Hunyadi. During this time, the castle was occupied by various rival forces, including mercenaries of King Matthias Corvinus from 1477 until about 1490, when Frederick's son King Maximilian I re-established Habsburg control over the area. This turbulent period interrupted the construction of the tower house (Wehrturm), the town's landmark with a height of 60 metres. The tower and other fortifications permitted a successful defense of the city against the Ottoman troops during the 1529 Siege of Vienna, while the surrounding area was devastated.
References:House of the Blackheads (Melngalvju nams) is a building situated in the old town of Riga. The original building was erected during the first third of the 14th century for the Brotherhood of Blackheads, a guild for unmarried German merchants in Riga. Major works were done in the years 1580 and 1886, adding most of the ornaments.
The structure was bombed to a ruin by the Germans June 28, 1941 and the remains demolished by the Soviets in 1948. The current reconstruction was erected from 1995 to 1999. Today the House of Blackheads serves as a museum and sometimes concert hall.