Princess Madeleine, fourth in line to the throne of Sweden, has become engaged to her wealthy New York banker boyfriend Christopher O'Neill, the royal palace said on Thursday.
Madeleine has been living with 38-year old O'Neill in New York and Swedish media has speculated for some time the couple were planning to marry.
"The date of the wedding has not been decided, but the plan is for it to be held during the summer of 2013," the palace said in a statement.
The royal family enjoys wide support among the public in otherwise egalitarian Sweden, though King Carl XVI Gustaf's reputation has been damaged by allegations he had an affair, visited a strip club and had connections to the underworld.
The marriage of Crown Princess Victoria, heir to the throne, to her personal trainer in 2010 and the birth of the couple's daughter earlier this year helped counteract some of the negative publicity.
Princess Madeleine has also been the focus of media attention after she called off wedding plans with her former boyfriend in 2010 after media reports of an affair with a Norwegian handball player.
In an interview published on the palace website, Madeleine said O'Neill — born and raised in Britain but who also has U.S. citizenship — had proposed at the beginning of October.
"I had thought about it for a while and wanted to wait for the right opportunity," O'Neill said. "But I knew that it was Madeleine I wanted to marry."
The 30-year old Princess, whose full name is Madeleine Therese Amelie Josephine, Duchess of Halsingland and Gastrikland, is the youngest of the king's three children.
First in line to the throne is Crown Princess Victoria, followed by her daughter, Princess Estelle.
Swedish media also continue to speculate on when Madeleine's older brother Prince Carl Philip will marry his girlfriend, a former topless model.