From bridesmaid to bride for Prince William's sister-in-law Pippa

Englefield : After turning heads at her sister Kate's wedding to Prince William, Pippa Middleton was Saturday graduating from bridesmaid to bride at what the British media were dubbing the society wedding of the decade.

The 33-year-old Pippa made global headlines with a figure-hugging outfit when Kate, now the Duchess of Cambridge, married William, second in line to the throne, in 2011.

On Saturday, she was on her way to exchange vows with wealthy financier James Matthews, 41, at a lavish wedding where William and Kate's young children, Prince George and Princess Charlotte, are expected to play a starring role.

The ceremony is taking place at St Mark's Church in Englefield, a quiet village in the Berkshire countryside west of London, near the Middleton family home.

The event will reportedly feature a flypast by a World War II-era Spitfire plane and a party afterwards in a £100,000 ($130,000, 115,000 euro) glass marquee.

The presence of senior royals means security is expected to be tight, and no-fly zones banning aircraft including drones have been imposed around the area.

William and Kate's three-year-old son Prince George -- Queen Elizabeth II's great-grandson and third in line to the throne, was to be a page boy.

Princess Charlotte, two, will be a bridesmaid.

William's younger brother Prince Harry is also expected to attend the wedding, likely with his US actress girlfriend Meghan Markle.

Harry's love life is a source of much speculation, prompting him last year to issue a rare warning to the media not to harass Markle.