As Edward was unmarried and had no children, Albert was the heir presumptive to the throne. Less than a year later, on 11 December 1936, Edward VIII abdicated in order to marry his mistress, Wallis Simpson, who was divorced from her first husband and divorcing her second. Edward had been advised by British Prime Minister Stanley Baldwin that he could not remain king and marry a divorced woman with two living ex-husbands. Edward chose abdication in preference to abandoning his marriage plans. Thus Albert became king, a position he was reluctant to accept. The day before the abdication, he went to London to see his mother, Queen Mary. He wrote in his diary, "When I told her what had happened, I broke down and sobbed like a child."

Why was Albert the heir presumptive to the throne?