Albert II was King of Belgium for two decades, ruling into the 21st Century.

He was born on June 6, 1934, in Stuyvenberg Castle, in Laeken, Brussels. His father was the eventual King Leopold III, and his mother was Astrid of Sweden. The reigning monarch when Albert was born was his grandfather, Albert I. That king died unexpectedly in 1934, and Leopold became king.

Young Albert suffered another tragedy the following year when his mother died in a car accident. His father remarried six years later, to Mary Lilian Baels, and they had three children together; thus, Albert, who already had a brother and a sister, eventually gained three more siblings.

Albert's older brother, Baudouin, was the heir to the throne when their grandfather died and their father became king. The young heir to the throne began his officially courtly studies when he was 7, learning in both Dutch and French. As well, he was a familiar sight at the side of his father during public appearances. Albert, meanwhile, grew up at court but slightly less out of focus.

Not long after Baudouin's 5th birthday, World War II began. The following year, 1940, Germany invaded Belgium. Albert's father had, at age 12, fought for a time against Germany in World War I. He had a different response to the Nazi invasion. After more than two weeks of blitzkrieg barrages, Leopold surrendered. Prime Minister Hubert Pierlot and many of the rest of the Belgian government fled to Allied lands, setting up a government in exile. The occupying German army held Leopold prisoner.

The king had enough time to ensure that his children were sent to safety: Albert and his sister and brother, Josephine-Charlotte and Baudouin, went to France and then on to Spain while their father stayed in Belgium and tried to negotiate a peace. It was while Leopold was under house arrest that he married Lilian.

Allied troops liberated Belgium in 1945, by which time Leopold and Lilian had been moved to Germany. Allied forces rescued them in the closing days of the war, but they did not return home because resentment of his actions was still too high; instead, they spent six years in Switzerland, in exile. Baudouin, meanwhile, continued his schooling, in Switzerland. Leopold's brother, Prince Charles, served as regent during this time.

Many people in Belgium still resented Leopold for surrendering to Germany. A referendum in 1950 resulted in more than half of people saying that were in favor his returning. This sentiment was nowhere near being universal, however, and when he and his family returned home, on July 22, 1950, he confronted a general strike, which turned violent and ended with deaths caused by soldiers firing into a crowd of protesters. A shocked Leopold agreed to grant his oldest son, then 20, regency powers. This occurred on August 11, 1950.

Opposition to Leopold's return as king was still very strong, and so he decided to abdicate. On July 17, 1951, Baudouin took the oath of office and became king.

Albert (left), then, became the heir to the throne and set his sights on marrying. He was in Vatican City for the coronation of Pope John XXIII, in 1958, when he met Donna Paola Ruffo di Calabria, whose paternal ancestors include to a World War I flying ace and maternal ancestors include the Marquis de Lafayette, famed French advisor to the American Revolutionary Army. The couple fell in love and, after a brief courtship, married, on July 2, 1959. They had three children: Philippe (1960), Astrid (1962), and Luarent (1963).

King Baudouin died of heart failure on July 31, 1993, in Motril, Spain. Albert then became king. The king continued in his role as head of state for two decades. He abdicated on July 21, 2013, he said for family and health reasons.