Tatiana Santo Domingo and Andrea Casiraghi
09/02/2013 AT 02:55 PM EDT
When Monaco royal Andrea Casiraghi married heiress Tatiana Santo Domingo
on Saturday, their wedding was unlike any other royal nuptials – the boho bride wore a simple garland of flowers in her tousled hair, instead of a crown.
New York-born Santo Domingo, 29, who has a 5-month-old son, Sacha
, with the second-in-line to the throne, wore a full-length Missoni gown with three-quarter-length sleeves and opted for flat silver sandals instead of heels for the late-morning ceremony in the grounds of the Prince's Palace, Hello!
– the eldest child of Princess Caroline and the late Stefano Casiraghi, who died in a speedboat accident in 1990 – wore a dark suit, white shirt and spotted blue tie.
After the ceremony the couple posed for photos with their Boston Terrier, Daphne. They were joined for an al fresco lunch by the pink palace's pool by 400 guests including the principality's ruler, Prince Albert, designer Karl Lagerfeld and members of the Missoni family.
Celebrations continued that evening with a party at the Hotel de Paris where the bride changed into another white Missoni gown, this time with longer sleeves, while the groom (who is the grandson of Hollywood-star-turned-Monaco-princess Grace Kelly) wore a tux.
The couple, who were introduced to each other by Casiraghi's sister Charlotte, dated for seven years before announcing their engagement
in July 2012.