Sir Elton John and David Furnish marry

Sir Elton John and David Furnish have married.

The showbiz couple tied the knot earlier today formally converting their civil partnership, and shared the moment on Elton's Instagram account.

"That's the legal bit done. Now on to the ceremony! #ShareTheLove @DavidFurnish (sic)," Elton captioned the shot of the beaming pair.

The couple will celebrate with a star-studded ceremony at their Windsor estate in Berkshire later, a spokesman said.

Superstar singer Elton and David first started dating in 1993 and were amongst the first couples in the UK to form a civil partnership in December 2005.

At the time the Rocket Man hitmaker spoke of his pride at the law change.

"Having our civil partnership was an incredible breakthrough for people that have campaigned for a long time - through the 60s and the 50s in England when it was so hard to be gay and hard to be open about it. And it was a criminal act.

"So for this legislation to come through is joyous, and we should celebrate it. We shouldn't just say, 'Oh, well we have a civil partnership. We're not going to bother to get married'. We will get married," he stated.

They are the proud parents of two sons; Zachary, three, and Elijah, 11 months. Both boys were born by the same surrogate mother.

Today's celebration is set to be a glitzy affair, with David and Victoria Beckham and Sharon and Ozzy Osbourne expected to be in attendance.

Elizabeth Hurley has already uploaded a snap of herself en route to the ceremony with her son Damian to her Instagram account.

Elton, 67, has also added more photos, including a shot of the invitation and a picture of the sun rising captioned "Good morning! Nice day for a wedding.#ShareTheLove (sic)."