Elizabeth increased England's naval power primarily by authorizing privateers to attack Spanish merchant shipping. This tactic proved particularly effective (albeit provocative) when Elizabeth came to the aid of the Netherlands during their war for independence from Spain. The Royal Navy itself was an inheritance from Elizabeth's father, Henry VIII, who expanded the navy from seven to twenty-four warships, including some of the largest vessels in the world. Henry also created the Navy Board and the Office of the Admiralty to administer the Navy, and built a naval dock at Portsmouth. For this reason, Henry was known as the "father" of the British Navy, and Elizabeth inherited both the fleet, and more importantly, the institutional and administrative apparatus for maintaining and expanding it.