Once Edward had made the choice to marry Wallis Simpson and renounce the throne, a short “Instrument of Abdication” was drafted, in which he would renounce his right to serve as ruling monarch. In signing the document—which he did on December 10, 1936—he also renounced the rights of his heirs (any children he had with Simpson) to the crown.
The Instrument took immediate effect. However, his abdication wasn’t formally announced until the next day, when, during an emotional speech broadcast across Britain on radio, he said, “[Y]ou must believe me when I tell you that I have found it impossible to carry the heavy burden of responsibility and to discharge my duties as King as I would wish to do without the help and support of the woman I love.”
He also declared his loyalty to his successor, his younger brother, who became King George VI. King George VI is also the father of Queen Elizabeth II.
As a result of the abdication, it is King George VI’s heirs, and thus the heirs of Queen Elizabeth II, who are in line for the British throne—and not the children of the former king.
Indeed, with his decision, Edward became the first—and so far, the only—British monarch to abdicate the throne voluntarily, and the first to abdicate the throne for any reason since 1399.
Edward and Wallis Simpson married in June of 1937 in small ceremony in Tours, France—notably not Westminster Abbey, the site of all official royal weddings. The former king held the title of Duke of Windsor.
The couple remained together until Edward’s death in 1972.