Frederick William I, Duke of Schleswig-Holstein-Sonderburg-Beck

Frederick William I, Duke of Duke of Schleswig-Holstein-Sonderburg-Beck (2 May 1682 – 16 June 1719) was a son of Duke August and his wife, Philippa Louisa of Lippe-Buckburg. He succeeded his father as Duke of Beck in 1689.

He converted to Roman Catholicism and joined the Army of the Holy Roman Empire. He died of his wounds in the Battle of Francavilla in Sicily in 1719.

Since he had no male heir, he was succeeded as Duke of Beck by his uncle Frederick Louis.

Marriage and issue

In 1708, he married Marie Antoinette (15.10.1692-1762), the daughter of Count Anthony Emmanuel of Sanfré, in Piedmont. They had two daughters:

• Maria Ana Leopoldina (b. Vienna 2.8.1717-7.2.1789 Torino). She was married in Vienna in 4.8.1735 to D. Manoel de Souza (21.7.1703-1759 in a fire, in prison, in Lisboa); senhor do Calhariz, in Portugal. Their son, D. Alexandre de Sousa Holstein (Lisbon 4.12.1751-13.12.1803) was senhor do Calhariz, count of Sanfré, Portuguese ambassador do the courts of Kopenhagen, Berlin and Rome.
• Johanna Amalia (b. 1719)

Ancestors