Prince Albert of Monaco has announced his engagement to the former South African Olympic swimmer Charlene Wittstock.
The announcement followed months of speculation that Prince Albert, 52, and Ms Wittstock, 32, would wed.
Prince Albert acceded to Monaco's throne in 2005 after the death of his father, Prince Rainier III.
He has two children, neither of whom are in line to the throne because they were born out of wedlock.
Ms Wittstock is a former teacher who competed for South Africa in the Olympic Games in Sydney in 2000.
Prince Albert has taken part in five Winter Olympics as a member of the Monegasque bobsleigh team.
The prince, whose mother was the American film star Grace Kelly, previously had a reputation as a playboy and a confirmed bachelor.
In 2002, the principality's constitution was changed so the Grimaldi dynasty to which Prince Albert belongs could continue through the female line if the ruler died without an heir.
The statement from the royal palace announcing the engagement did not mention any wedding date.