Duchess Kate's brother James Middleton engaged

The younger brother of Duchess Kate has proposed to his French girlfriend. Photo / Getty Images

James Middleton says he "couldn't be happier" to be engaged.

The 32-year-old brother of Duchess Catherine recently proposed to his French girlfriend, Alizee Thevenet, after they moved in together in West London and has taken to social media to confirm the happy news.

He wrote on his Instagram page: "She said OUI ... Our secret is out but we couldn't be happier to share the news #jalizee (sic)"

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❤️She said OUI ❤️ . Our secret is out but we couldn’t be happier to share the news 🥂🍾 #jalizee 🇬🇧🇫🇷

A post shared by James Middleton (@jmidy) on Oct 6, 2019 at 6:37am PDT

A source had previously confirmed James had told his friends about the news.

The insider shared: "They've got engaged. Alizee has been wearing a beautiful sapphire sparkler. They've been keeping the engagement secret, but news has started to leak out among their friends. They'll be announcing it formally next week."

James and Alizee met last year after meeting at the South Kensington Club, a private members establishment in London, when Alizee gushed over his Cocker Spaniel, Ella.

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Sail away with me ⛵️ ☀️

A post shared by James Middleton (@jmidy) on May 7, 2019 at 10:23am PDT

A friend revealed at the time: "After Alizee went back to her table, James asked the waiter to give her a note saying: 'I never normally do this, but would you like to go for a drink with me?'

He also picked up their tab. A few weeks later, they went out for a drink together. It wasn't until after they'd met for a drink that Alizee realised who he was - one of her friends had to tell her. They met thanks to Ella."

James split from Donna Air, 40, in December 2017 after almost five years together.

She said at the time: "James and I are no longer an item. We parted ways in December but remain the very best of friends and always will be."