Pop superstar Elton John and Canadian-born filmmaker David Furnish smiled and waved to hundreds of fans on Wednesday after celebrating their same-sex union in Windsor, England.

Their civil partnership ceremony was one of 687 taking place across England and Wales on Wednesday, the first day they can legally take place.

The United Kingdom's new civil partnerships legislation – which does not use the word marriage – came into effect on Monday in Northern Ireland, then on Tuesday in Scotland.

David Furnish and Elton John outside Windsor's Guildhall, after taking their vows, Wednesday, Dec. 21. (AP Photo/Haydn West)

The John-Furnish ceremony took place in the same building where Prince Charles and Camilla Parker-Bowles were married last spring.

Clair Williams, the woman who presided over the royal ceremony in April, led this ceremony as well.

John, 58, and Furnish, 43, are holding a reception for about 700 people at Sir Elton's nearby estate.

Those expected to attend include Canadian singer Bryan Adams, actress Elizabeth Hurley, soccer star David Beckham and his wife Victoria, and financier Conrad Black.

Furnish, who grew up in Scarborough, Ont., met John in 1993.

The ceremony was attended by friends and family, including John's mother, Sheila, and stepfather Fred, and Furnish's parents Gladys and Jack, who flew in from Canada.

The new civil partnerships legislation gives same-sex couples the right to form legally binding partnerships.

It also entitles them to the same tax and pension rights as married couples.

The law requires the couples wishing to form a partnership to register with their local municipal councils. Only gay and lesbian couples are allowed to register for the partnership option.

Gay marriages are legal only in Canada, the Netherlands, Belgium and Spain. In the U.S., Massachusetts alone allows gay marriage, while Vermont and Connecticut permit gay civil unions.