Waléran, the first Count of Arlon, built a fortified chateau at the top of the town during the 11th century. Along with the town ramparts, this was completely destroyed in 1558 when Arlon was pillaged by the troops of the Duc de Guise. When the Capuchin monks arrivedin Arlon in 1621, they built their abbey on the ruins of the castle.
In 1681 a Vauban-type fortified wall was built transforming the abbey into a citadel. After being the victim of alightning strike in 1719, it was decided to dedicate the church to Saint Donat. The old religious foundation of the Capuchins was finally abandoned in 1796 - Only the church survived and was then restored and renovated during the 20th century.
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.