Prince Guillaume of Luxembourg, heir to the throne, married Belgian countess Stephanie de Lannoy on Friday in a civil ceremony on the eve of a religious wedding to be attended by royalty from across Europe.

The 28-year-old bride, who will acquire Luxembourg citizenship through marriage, and the 30-year-old groom tied the knot at city hall in what was a departure from tradition, as previous royal ceremonies were held at the Grand-Ducal palace.

Flanked by around 20 family members, the pair -- she in a two-piece beige ensemble and he in a dark suit and striped tie -- walked several hundred metres (yards) from the palace to city hall as about a thousand Luxembourg residents looked on and more than 200 children waved the grand duchy's red, white and blue flags.

The ceremony was closed to television cameras and attended by a tight-knit group including Grand Duke Henri and Grand Duchess Maria Teresa of Luxembourg, Count Philippe de Lannoy and siblings from both sides. The bride's mother died in late August.