COPENHAGEN (Reuters) -Denmark’s King Frederik X ascended the throne on Sunday, succeeding his mother, Queen Margrethe II, who formally abdicated after 52 years as monarch, with big crowds gathered in the capital to witness history. Margrethe, 83, stunned the nation on New Year’s Eve when she announced she planned to become the first Danish monarch in nearly 900 years to voluntarily relinquish the throne. The succession was formalized the moment Margrethe signed the declaration of her abdication during a meeting of the Council of State at parliament, the royal palace said. Denmark, one of the o…