control of the Dutch Republic, which in 1647 had given Johann Moritz von Nassau-Siegen administrative control over the city. He approved a renovation of Schwanenburg
ISBN 978-1-84603-009-3. Staff, Gary. German Battleships: 1914–1918. 1: Deutschland, Nassau and Helgoland Classes. Oxford: Osprey Books. 2010. ISBN 978-1-84603-467-1