Some 20,000 people, waving Danish and Australian paper flags, cheered Frederik and Mary Donaldson at the Christian IX palace, one of four Renaissance-style mansions that make up Amalienborg Castle.
Visibly happy but also a bit overwhelmed by the huge crowd, Donaldson put her arm around Frederik as their parents joined them - Queen Margrethe and her French-born husband Prince Henrik on one side, and John Dalgleish Donaldson and his wife, Susan Moody, on the other.
Despite repeated calls from the crowd for the couple to share a kiss, Frederik elegantly gave her a peck on the hand.
Frederik and Donaldson will be married May 14 at Copenhagen's Lutheran neoclassicist cathedral, Our Lady's Church.
At a state council meeting earlier in the day, Margrethe told the Danish government that her 35-year-old son, the heir to the throne of Europe's oldest ruling monarchy, would marry the 31-year-old from Hobart, Tasmania. After the meeting, Frederik and Donaldson, their parents and the government members posed for an official photo.
"We think it's great," said Steve Thurlow, a businessman from Hobart who was in the city for a business trip.
The couple met during the 2000 Olympics in Sydney but the romance was kept secret for a year. In February 2002, the palace finally confirmed that Frederik was dating Donaldson.
In early 2002, Donaldson moved to Copenhagen and started studying Danish. In recent months, she has been learning about the history of this Scandinavian country of 5.3 million.
Donaldson is the first Australian-born woman to stand in line to become a European queen. Before she can marry Frederik, she must swap her dual citizenship in Australia and Britain to become a Danish citizen and join Denmark's Lutheran Evangelical Church.
Once married, Donaldson will become Crown Princess Mary. Margrethe repeatedly has said she has no plans to step down to let her son assume the throne.
Frederik will become King Frederik X and the sixth Danish monarch of the Glucksburg house.
Denmark's popular crown prince is a major in the army and the air force, and a commander in the navy. Frederik studied international relations and government at Harvard and received a master's degree in political science in 1995 in Denmark. He worked briefly at Denmark's U.N. mission in New York and the Danish Embassy in Paris.
Donaldson's parents emigrated from Scotland to Australia in 1963 and became Australian citizens in 1975. Her mother, Henrietta Clark Donaldson, died in 1997 and her father, a professor of mathematics at Oxford University in Britain, remarried in 2001 to Moody, a
Donaldson, who worked in advertising, public relations and real estate, has two sisters and a brother. She worked as a project consultant for the Danish subsidiary of Microsoft.
By Jan M. Olsen