House of Windsor
The House of Windsor, previously called the House of Saxe-Coburg-Gotha, is the Royal House of the United Kingdom of Great Britain and Northern Ireland. In 1917, during World War I, anti-German feeling among the people resulted in the Royal Family changing all of their German titles and surnames for English-sounding versions. The Royal House and Family was renamed Windsor by an Order-in-Council of King George V.
The German name came via Queen Victoria's marriage to Prince Albert, son of Duke Ernst I of Saxe-Coburg-Gotha, in February 1840.
However, the Order only referred to all descendants of Queen Victoria in the male line, but not necessarily by female descendants. In April 1952, two months after her accession, Queen Elizabeth II ended confusion over the dynastic name when she declared to the Privy Council her “Will and Pleasure that I and My children shall be styled and known as the House and Family of Windsor, and that my descendants who marry and their descendants, shall bear the name of Windsor.”
Later, on February 8, 1960, The Queen issued another Order-in-Council, confirming that she and her four children will be known as the House and Family of Windsor, and that her other male-line descendants (except those who are "HRH" and a Prince or Princess) will take the name "Mountbatten-Windsor".
Any future monarch could change the dynasty name if he or she chose to do so. Another Order-in-Council would override those of George V and Elizabeth. For example, if the Prince of Wales accedes to the throne, he could change the royal house to "Mountbatten" in honour of his father, and of his uncle Louis Mountbatten.
King George V's reign began in 1910 under the House of Saxe-Coburg-Gotha and ended in 1936. Though the Irish Free State left the United Kingdom in 1922, the actual name of the kingdom was not changed until 1927, when he also became King of Ireland. From 1927, the monarch also became the king or queen of many Commonwealth Realms, including, Australia, Canada, the Irish Free State, New Zealand, Union of South Africa, etc. Previously they had been monarchs in, not of, those states, through a shared Crown of the British Empire. After 1927, it became a shared monarch wearing multiple crowns. Until 1947, the king was also styled Emperor of India.