Although the Hanoverian kings all had more than one name, they always chose the first as king, but when Queen Victoria, who had been christened Alexandrina Victoria, came to the throne, she chose her second name. Although Queen Victoria expressed her wish that all her male descendants should be christened Albert, this was largely disregarded after her death.
Her eldest son, Prince Albert Edward, also chose his second name as Edward VII, because it was popular in England; there having been three pre-Conquest and six subsequent kings of this name.
George V and Edward VIII took their first names as kings; but after the abdication of Edward VIII, he was succeeded by his brother Prince Albert, Duke of York, who chose to reign under his last name as George VI, probably because he wished to establish continuity with his father, and Albert, a foreign name, had strong associations with The Prince Consort.
When his daughter, Princess Elizabeth, succeeded to the throne in 1952, it was a foregone conclusion that she would select her first name as her regnal name, as this was the name by which she had always been known. In contrast it was not clear whether her son, Charles, would take his first name as his regnal name, Charles being considered an unlucky name for a monarch. It had been thought that he might choose George, his last name, as his regnal name and become George VII. This proved not to be the case, however, when it was announced in September 2022 that he would be Charles III and that we would therefore cease being Elizabethans and become Caroleans.
Image, top: Albert, Victoria and their nine children, 1857. Left to right: Alice, Arthur, Prince Albert, Albert Edward, Leopold, Louise, Queen Victoria with Beatrice, Alfred, Victoria, and Helena.