A Dutch privateer like Murat Reis the Younger, Siemen also chose the life of a Barbary pirate. His motives remain a mystery but he quickly became one of the most famous renegades to join the Barbary Coast, notably forming a partnership with John Ward. He eventually abandoned piracy and settled in Marseilles, France, where he helped the French work against his former comrades. He is said to have been captured in Tunis and beheaded.
Siemen was also known as ‘Simon the Dancer’