Burg Wiener Neustadt Burg Wiener Neustadt is a castle in Wiener Neustadt , Lower Austria , Austria . History . The first castle in Wiener Neustadt was built in 1193 / 94 , when at the same time , the city walls of Wiener Neustadt were built . The costs were paid from the ransom of Richard the Lionheart . This castle is said to have stood on the north - eastern corner of the city , but there is no archaeological evidence of this . When that castle became too small , however , the newer castle was built on the present site by Leopold VI the Glorious at the beginning of the 13th century . Since the area is quite marshy , it was built on wooden piles . Under Frederick II the Warlike it was finally surrounded by a moat , outer walls and towers . In 1246 east of the castle the Battle of the Leitha was fought , when Frederick II was killed . A monument at Burgenland road still reminds of it . In 1260 the castle was first mentioned in documents . The wall was removed , however , under Otakar II of Bohemia already in 1253 and built up again in the late 13th Century . During an earthquake in 1348 the castle collapsed . This led to a larger new building under Leopold III starting in 1378 . On the terrace that was built over the tomb chapel of Leopold IV Peter Pusika on behalf of Duke Ernest the Iron built the " Gottsleichnamkapelle " ( God ' s Body Chapel ) and later , on behalf of Emperor Frederick III the St George ' s Chapel in the newly created West Wing . In many places of the castle the inscription “ A . E . I . O . U . ” can still be found , which dates back to Frederick III . When Frederick III . refused to dismiss Ladislaus the Posthumous from his guardianship , this led to creation of the Mailberg Confederation ( " Mailberger Bund " ) and a siege of the castle in 1452 by an Estates ' army of 16 , 000 . Only after negotiations Frederick dismissed his ward . Subsequently he founded the St . George ' s Order and made the castle available as the Order ' s seat . The seat , however , was repealed in 1598 . 1486 saw a renewed siege by Matthias Corvinus , which ended after two years with the defenders ' surrender . Only after Matthias ' death in 1490 the occupation troops were expelled again from castle and city . Under Emperor Maximilian I , the castle lost the status of permanent residence and it became only a retreat of the emperor . Maximilian was in buried St . George ' s Chapel , although previously a tomb had been built in the Innsbruck Court Church . In 1521 Ferdinand I retreated to the castle because of the resistance of the Protestant Estates . Subsequently , though , the Vienna city government was arrested , and they were brought to trial ( " Wiener Neustädter Blutgericht " , i . e . Wiener Neustadt Bloody Trial ) and executed here . However , also other celebrities were detained in a tower that was adapted as a state prison , the " Rákócziturm " ( Rákóczi Tower " ) , such as Francis II Rákóczi or Peter Count Zrin . During the first Turkish Siege of Vienna in 1529 , the castle was attacked but not conquered . During the second siege in 1683 it was not attacked . In the meantime , however , in the years 1608 and 1616 fires caused major damage . In 1743 1 , 400 French prisoners of war were detained in the castle . A little later , a pestilential epidemic broke out , which claimed many victims . The castle therefore remained closed because of the risk of infection for two years after withdrawal of the survivors . Thereafter , it was hardly used and neglected . In 1751 the Theresian Military Academy was established in the castle by Maria Theresa of Austria . This involved numerous changes which were implemented by Viennese architect Matthias Gerl . In 1768 , an earthquake again caused severe damages , which made the building uninhabitable . Three of the four towers had to be removed . In the east wing new rooms were furnished for the emperor . In the place of God ' s Body Chapel , the main staircase was erected . After World War I , the military academy was closed , but reopened in 1934 . During the bombings at the end of World War II in 1944 / 45 , the castle – just like the city as a whole – was so badly damaged that only the outer walls remained standing . It was rebuilt after the war so that the military academy was able to resume operations in 1958 . The castle , which had always been the sovereign ’ s property , is now owned by the Republic of Austria . Buildings . St . George ' s Cathedral . The St . George ' s Cathedral is a late Gothic hall church with three naves . It was created by Peter von Pusica and was built in the years 1440 to 1460 . The original chapel was called St . Mary ' s or Our Lady ' s Chapel . Under Frederick III . it was renamed to St . George ' s Chapel as the seat of the Knights of St . George ' s Order . The Chapel was heavily destroyed in World War II . Only one pillar remained original . It was rebuilt after 1945 using the white sandstone from Kaisersteinbruch quarry . In 1784 , the former bishop ' s see was moved to St . Pölten . Only in 1963 Wiener Neustadt became the see of the military bishop and the chapel was promoted to cathedral status in 1987 under military bishop Alfred Kostelecky . Academy Park . The originally swampy area between the town and Leitha river was drained under Frederick III . Also a zoological garden was created , which existed until 1751 . The 106 - hectare ( 262 - acre ) area was later converted into a park and has been open to the public since Maria Theresa . References . " This article was initially translated from the German Wikipedia . "