H.M.S. KING EDWARD VII - Public domain portrait photograph

The House of Windsor is the royal house of the United Kingdom and the other Commonwealth realms. Founded by Ernest Anton, the sixth duke of Saxe-Coburg-Saalfeld, it is the royal house of several European monarchies, and branches currently reign in Belgium through the descendants of Leopold I, and in the United Kingdom and the other Commonwealth realms through the descendants of Prince Albert. It succeeded the House of Hanover as monarchs in the British Empire following the death of Queen Victoria. The name was changed from Saxe-Coburg and Gotha to the English Windsor in 1917 because of anti-German sentiment in the British Empire during World War I. Windsors were originally a branch of the House of Saxe-Coburg and Gotha that have provided five British monarchs to date, including four kings and the present queen, Elizabeth II. The name had a long association with the monarchy in Britain.

Throughout the 18th and 19th centuries, the Royal Navy was the largest navy in the world and maintained ascendancy over its rivals through superiority in financing, tactics, training, organization, hygiene, dockyard facilities, logistical support, and warship design and construction. The French Revolutionary Wars and Napoleonic Wars saw the Royal Navy reach a peak of efficiency, dominating the navies of all adversaries, which spent most of the war blockaded in ports. Between 1815 and 1914, the Navy saw little serious action, owing to the absence of any opponent strong enough to challenge its dominance. Due to British leadership in the Industrial Revolution, unparalleled shipbuilding capacity, and financial resources, British naval warfare underwent a comprehensive transformation, brought by steam propulsion, metal ship construction, and explosive munitions. In 1859, the fleet was estimated to number about 1000 vessels. In 1889, Parliament passed the Naval Defence Act, which formally adopted the 'two-power standard', which stipulated that the Royal Navy should maintain a number of battleships at least equal to the combined strength of the next two largest navies. During the First World War, the British advantage proved insurmountable, leading the German navy to abandon any attempt to challenge British dominance. The Royal Navy had established a blockade of Germany, closed off access to the English Channel, and mined the North Sea. During the Dardanelles Campaign against the Ottoman Empire in 1915, the Royal Navy suffered heavy losses during an attempt to break through the system of minefields and shore batteries defending the straits. The most serious danger to the British Navy and merchant fleet came from the attacks of German U-boats. Unrestricted submarine warfare raised the prospect of Britain being starved into submission in 1917. The introduction of convoys brought the U-boat threat under control. In the inter-war period, the Washington and London Naval Treaties imposed the scrapping of some capital ships and limitations on new construction. The Royal Navy was stripped of much of its power. The re-armament of the Royal Navy restarted in 1932 - with the construction of new battleships and first purpose-built aircraft carriers. At the start of World War II in 1939, the Royal Navy was the largest in the world, with over 1,400 vessels, including 7 aircraft carriers, 15 battleships and battlecruisers. The Royal Navy suffered heavy losses in the first two years of the war with the most critical struggle of the Atlantic defending Britain's vital commercial supply lines against the U-boat attacks. The Navy was vital in guarding the sea lanes that enabled British forces to fight in North Africa, the Mediterranean, and the Far East. Naval supremacy was essential to amphibious operations such as the invasions of Northwest Africa, Sicily, Italy, and Normandy. By the end of the war the Royal Navy comprised over 4,800 ships, and was the second-largest fleet in the world. After the Second World War, the increasingly powerful United States Navy took on the former role of the Royal Navy as a global naval power and police force of the sea. The decline of the British Empire and the economic hardships forced the reduction in the size and capability of the Royal Navy. One of the most important operations conducted by the Royal Navy after the Second World War was the 1982 Falkland Islands War. Despite losing four naval ships, the Royal Navy fought and won a war over 8,000 miles (12,000 km) from Great Britain. The Royal Navy also took part in the Gulf War, the Kosovo conflict, the Afghanistan Campaign, and the 2003 invasion of Iraq.

In the 17th and 18th centuries, the Royal Navy engaged in a long struggle with the Spanish, Dutch, and French for maritime supremacy. Starting with Elizabeth I, the British navy became England’s major defense and offense force by which the British Empire was extended around the globe. In the 19th century, the Royal Navy helped enforce what became known as the Pax Britannica. During World War I navy's main mission was the protection of shipping from submarine attacks. During World War II the Royal Navy became second in size to the U.S. Navy