Model Kendra Spears is set to join the world's royal families after becoming engaged to marry Prince Rahim Aga Khan.

The 24-year-old Seattle, Washington native will become His Highness the Aga Khan's daughter-in-law when she weds his eldest son.

The Aga Khan is the spiritual leader of the global community of the Shia Ismaili Muslims, and Spears has agreed to wed under Islam law, but a date for the ceremony has not yet been set.

Confirming the news on her page, Spears writes, "Thank you all for the kind tweets! We're very excited!"

Spears won a Ford Models competition in 2008 and has appeared in publications like Vogue and Elle. She has also appeared in campaigns for Calvin Klein and Emporio Armani.