Royals Grace Kelly's Granddaughter Charlotte Casiraghi Engaged to Dimitri Rassam Princess Caroline's eldest daughter Charlotte was wearing a diamond ring on her left hand at the Bal de la Rose By Peter Mikelbank and Maria Pasquini Maria Pasquini Associate Editor, Human Interest - PEOPLE People Editorial Guidelines Published on March 25, 2018 01:30 PM Share Tweet Pin Email Charlotte Casiraghi and her boyfriend Dimitri Rassam are engaged! Princess Caroline of Monaco’s eldest daughter confirmed her engagement on Saturday by wearing a diamond ring on her left hand as she and Rassam attended their first official Monaco event together, the 64th annual Bal de la Rose in Monte Carlo on Saturday. The couple is set to wed in July. A source tells PEOPLE they became engaged three weeks ago while on a family ski vacation with Princess Caroline in Austria. Although Charlotte, 31, who is ninth in line to Monaco’s throne, and the 36-year-old film producer (his credits include Netflix’s The Little Prince) have yet to comment publicly on their engagement, their happy news was first reported by Hola! magazine earlier this month. PEOPLE has reached out to the Prince’s Palais for a statement. Pascal Le Segretain/ SC Pool - Corbis/Corbis via Getty Images Royal Love! Grace Kelly’s Granddaughters Charlotte Casiraghi and Jazmin Grimaldi Have New Men in Their Lives Sources previously confirmed to PEOPLE that Charlotte and Dimitri quietly began seeing each other in Dec. 2016 after being introduced by friends over dinner. Charlotte appeared to confirm the pair’s relationship in March 2017 when she wore a vintage black velvet dress to the Bal de la Rose, which was the exact same outfit her mother had previously worn to a high-profile Monaco event she had attended with Dimitri’s mother Carole Bouquet — a former Bond girl — in December 2000. Stephane Cardinale - Corbis/Corbis via Getty Images The granddaughter of Grace Kelly and the film producer, who have been inseparable since, living together in LA, Paris and Monaco, share similar backgrounds. Both are graduates of the Sorbonne University in Paris, and each have children from previous relationships: Charlotte has a 4-year old son, Raphael, with comedian Gad Elmaleh, and Dimitri has a daughter from his marriage to model Masha Novoselova. Want to keep up on the latest from PEOPLE? Sign up for our daily newsletter to get our best stories of the day delivered straight to your inbox. This is the second engagement within a month for Monaco’s ruling family. Charlotte’s cousin Louis Ducruet announced his engagement to longtime girlfriend Marie Chevallier on Feb. 21. Saturday’s Bal de la Rose was also attended by Charlotte’s brother Pierre Casiraghi and wife Beatrice Borromeo, who are expecting their second child together. Sources at the Bal tell PEOPLE Beatrice is due in May. The couple, who married in two lavish ceremonies in Summer 2015, already have one-year-old son Stefano.