Belgium's King Albert II has formally abdicated in favour of his son Crown Prince Philippe. In his final address as king on Sunday, the 79-year-old monarch said his country must remain a "source of inspiration" to Europe. On Saturday, he had urged Belgians to give his 53-year-old son their support. He also stressed his wish was that Belgium - split between the Dutch-speaking north and the French south - remained united. Earlier this month, Albert said he was no longer well enough to carry on. His resignation after nearly 20 years on the throne comes on Belgium's national day. Philippe - an Oxford- and Stanford-educated trained air force pilot - will shortly become the country's seventh king. Belgium has a constitutional monarchy in which the king plays a largely ceremonial role. Constitutional crises In an emotional ceremony at the royal palace in Brussels, the former monarch told his son: "You have all the emotional and intellectual qualities to serve our country well." He thanked an audience of some 250 dignitaries and political leaders "for all that you have achieved during my reign". Albert also thanked his wife, Paola, for the support she had given him during his reign, and was in turn thanked by Prime Minister Elio Di Rupo for his service to his country. Mr Di Rupo holds the political power in the 183-year-old parliamentary democracy. Albert then embraced his son and signed the official abdication papers, ending his reign. Later on Sunday, Philippe will takes the oath before politicians at the nearby parliament building. One of the duties the monarch does have is trying to resolve constitutional crises. King Albert exercised his authority in mediating between political leaders on the formation of a government during the 2010-2011 parliamentary stalemate, when Belgium was left without a government for 541 days after elections failed to find a clear winner. Tensions between the Dutch-speaking and French communities sometimes run high, and the issue has brought down several governments, creating frequent political instability. Respect for the royal family, though, is one of the few factors that crosses the communal divide. King Albert's abdication comes only three months after Queen Beatrix of the neighbouring Netherlands vacated the Dutch throne in favour of her son Willem-Alexander.