Monaco's palace says Andrea Casiraghi, the oldest son of Princess Caroline and second in line to the principality's throne, is to marry at the end of the month.
The Monaco palace said he would marry Colombian heiress Tatiana Santo Domingo on August 31, but gave no details on the wedding. The couple have been engaged for a year and she gave birth to a son in March.
The 29-year-old Casiraghi is the nephew of Monaco's ruling sovereign, Prince Albert II, who himself ended decades of bachelorhood in 2011 when he wed South African former Olympic swimmer Charlene Wittstock.