The Île Sainte-Marguerite island is most famous for its fortress prison (the Fort Royal), in which the so-called Man in the Iron Mask was held in the 17th century.
The island is first known to have been inhabited during Roman times, when it was known by the name Lero. In 1612, ownership of the island passed from the monks of Saint-Honorat to Claude de Lorraine, Duke of Chevreuse. Shortly after, construction of a fort on the island (to become the Fort Royal) began. In 1635, the island was captured by the Spanish and recaptured by the French two years later.
Towards the end of the 17th century, the Fort Royal became home to a barracks and state prison. During the 18th century, the present-day village of Sainte-Marguerite developed, thriving on the spending power of the soldiers stationed on the island.
The Fort Royal was home to a number of famous prisoners until its closure in the 20th century. As well as the Man in the Iron Mask, a mysterious prisoner whose identity remains unknown, Abd al-Qadir al-Jaza'iri (an Algerian rebel leader), Marquis Jouffroy d’Abbans (inventor of the steamboat) and Marshal Bazaine (the only successful escapee from the island) have all spent time there.
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.