Sources tell PEOPLE that invitations to the civil ceremony wedding will go out in mid-May, with a civil ceremony being held in Monaco on either June 21 or 29.

Mark your calendars! Monaco’s royal family is planning a wedding.

Charlotte Casiraghi, 32, daughter of Monaco’s Princess Caroline, will wed her film producer fiancé, Dimitri Rassam, 37, in June, according to Paris-Match.

Confirming the news, sources tell PEOPLE that invitations to wedding will go out in mid-May, with a civil ceremony being held in Monaco on either June 21 or 29.

While details are still be finalized, sources suggest the separate religious celebration will be held in July at either St. Remy de Province or the Mediterranean island of Pantalleria off Sicily, where the groom’s mother, actress and model Carole Bouquet, maintains a 13-acre vineyard estate.

The couple have a 5-month-old son named Balthazar together. Casiraghi, the eldest granddaughter of Princess Grace, has never been married. She also has a 5-year-old son Raphael from a previous relationship with comedian Gad Elmaleh. Rassam, who has been married before, has a 7-year-old daughter.

Dimitri Rassam and Charlotte Casiraghi
Rose Ball 2018 To Benefit The Princess Grace Foundation In Monaco
Dimitri Rassam and Charlotte Casiraghi
| Credit: Pascal Le Segretain/ SC Pool - Corbis/Corbis via Getty
Hollywood star Grace Kelly became Princess Grace on her wedding day in 1956
| Credit: Michael Calcagno

The couple have known each other for years and were connected by friends in Paris over Christmas in 2016. Casiraghi first signaled her relationship by wearing a vintage black velvet gown at the 2017 Bal de la Rose (which several sharp-eyed royal watchers recognized was the exact number her mother previously wore to a high-profile Monaco event that she had attended alongside Rassam’s mother, Carole Bouquet, in December 2000).

They confirmed their engagement a year later at the same event, when Casiraghi debuted a large pink diamond engagement ring with Rassam at her side.

Last Saturday, at the 65th annual edition of the Bal, Casiraghi and Rassam were all smiles, posing with their mothers, brothers, sisters and their spouses, including Rassam’s brother Louis and his wife.

From left: Princess Caroline’s youngest daughter Alexandra of Hanover, Dimitri Rassam, Charlotte Casiraghi, her brother Pierre Casiraghi and wife Beatrice Borromeo, Tatiana Santo Domingo and husband Andrea Casiraghi.

While Casiraghi purposefully was not given the title of “Princess,” she is currently 11th in the line of succession to the Principality’s throne. With Prince Albert‘s agreement, her son Balthazar could become 12th in the line of succession under Monaco’s civil code, which allows children to enter the line with the subsequent marriage.

Princess Caroline and Prince Albert

Despite press attention, the couple have sought to balance their privacy against public curiosity. In January, they took the extreme action of renouncing rumors concerning their reported split by threatening legal action.

Casiraghi and Rassam will not be the only marriage celebrated in Monaco in the coming months. Princess Stephanie’s son Louis Ducruet and his fiancée Marie Chevallier are expected to tie the knot this summer as well.