A whirlwind romance: Chelsy battles with bride's billowing dress as William and Harry lead Royal party at society wedding of year Princes' old friend Thomas van Straubenzee has wed Lady Melissa Percy in an extravagant ceremony A smartly-dressed Pippa Middleton among guests arriving at St Mary's Church, Alnwick Princesses Beatrice and Eugenie also among the congregation By Kerry Mcdermott and Anna Edwards The Duke of Cambridge and his brother Prince Harry arrived in Northumberland today for the wedding of their old friend Thomas van Straubenzee and society bride Lady Melissa Percy. Excitement was mounting in Alnwick as the princes arrived in the sunshine ahead of this evening's lavish ceremony. Crowds gathered to see Lady Melissa Percy in her billowing white gown that was embellished with lace, and waved as her beaming bridesmaids - including Prince Harry's Zimbabwean ex-girlfriend Chelsy Davy - walked through the town. Dessed in pale espresso floor-length gowns and clutching bouquets, the bridesmaids helped the excited-looking bride with her full dress, which was whipped up by the north east winds. Bride and breezy: A gust of wind blows Lady Melissa Percy's veil into the air as Chelsy Davy (seen left) and her fellow bridesmaid attempt to keep the bride's gown under control Big day: Bride Lady Melissa is accompanied by her father the Duke of Northumberland and two bridesmaids - including Prince Harry's ex Chelsy Davy (right) - as she makes her way into St Mary's Church in Alnwick Bridesmaid Chelsy Davy looked delighted as she walked into the church - despite having to face her ex-boyfriend Prince Harry and his new girlfriend, Cressida Bonas Don't upstage the bride! The high society wedding was eagerly watched by many Alnwick residents, who turned out in their droves to watch the lavish ceremony Just get me to the church on time! Lady Melissa Percy makes her way to the church with her father Ralph Percy, the 12th Duke of Northumberland he bride looked ecstatic as she arrived at the church gates and gave enthusiastic hugs to those waiting Pippa Middleton, resplendent in a patterned peplum dress with co-ordinating hat and heels, was greeted at the church gates by cries of 'beautiful' from the crowd. Princesses Beatrice and Eugenie are also among the Royal contingent at today's ceremony. The sisters - Beatrice wearing blue and Eugenie in green - were spotted hugging other guests at the gate before walking into the picturesque church. Society girl Cressida chose a blue and white maxi dress, which she teamed with a blue sequinned jacket and a cream flower in her hair. The sprawling Alnwick estate has doubled as Hogwarts School in the Harry Potter movies. For better or worse: The couple shrugged off the rain to enjoy a kiss after their Northumberland ceremony Husband and wife: The Duke and Duchess of Northumberland's daughter Lady Melissa Percy is seen with her newly-wed husband Rain can't dampen their spirits! The bride's mother said that the miserable weather had not troubled the couple, who were too excited about their wedding to care about the weather Prince Harry braves the rain, while his girlfriend Cressida Bonas seemed in a sunny mood, laughing out loud after the service Who has he spotted? Prince Harry, who was among ex-goirlfriend Chelsy Davy and current love Cressida Bonas, was pictured with raised eyebrows - but who or what had prompted his reaction is unknown Prince William and his brother's ex-girlfriend, graduate Chelsy Davy, gathered together to applaud the newly weds A snap of William apparently arriving last night at nearby Alnmouth railway station has been circulating on Twitter. The Duke of Cambridge was without his heavily pregnant wife Kate, but there were still plenty of glamorous female guests in attendance - including her sister Pippa Middleton, Prince Harry's girlfriend Cressida Bonas, Princesses Beatrice and Eugenie, and Holly Branson. The Duchess of Northumberland, mother-of-the-bride, told The Journal newspaper ahead of today's ceremony: 'We are really excited. The weather forecast is not great but Melissa and Thomas do not seem to mind. Whatever the weather it is going to be a wonderful day. Lady Melissa is a 26-year-old tennis coach while the groom is a chartered-surveyor and long-time friend of both William and Harry. What a beautiful day! Lady Melissa Percy, 26, is greeted by her close friend and bridesmaid Chelsy Davy before she walked up the aisle The bride, who is the Duke's second daughter, could be seen grinning at her father as she made her way to the church Hang on! The bride struggled to control her veil as a gust of wind blows her wedding dress over her head before her marriage What an entrance! Lady Melissa Percy was seen seen arriving in an ornate horse drawn carriage for her wedding to Thomas Van Straubenzee The brothers were at the 30-year-old's London stag do earlier this month. Lady Melissa is the Duke of Northumberland's second daughter. When her sister Lady Katie, a motorbike mechanic, married at St Michael's Church two years ago, Pippa Middleton was a guest. She is friends with Earl George Percy, the Duke's elder son. Chelsy Davy, Harry's former girlfriend, will also be there to attend to the bride who will leave Alnwick Castle in a restored horse-drawn carriage that is almost 200 years old. The Duke and Duchess of Northumberland's daughter Lady Melissa Percy arrives to marry her chartered surveyor boufriend The couple appeared to have plumped for a woodland theme, with the young members of the bridal party sporting Robin Hood and green woodland fairy outfits Uniformed police and plain clothes officers kept a close eye on the hundreds gathered to watch the procession. Block heeled shoes, ankle-length dresses and smaller hats were very much in fashion amongst the guests. The couple appeared to have chosen a woodland theme for their nutials, as their pages and young bridesmaids were dressed as Robin Hoods and fairies in green. Looking dapper: Prince Harry and Prince William are seen arriving for the wedding of Lady Melissa Percy and Thomas van Straubenzee Pippa's heavily pregnant sister the Duchess of Cambridge was unable to attend - but the younger Middleton still managed to turn heads with a monochrome outfit and hat Finery: Prince Harry's girlfriend Cressida Bonas, left, wearing a blue and white maxi dress and a sequinned blue jacket, walked into the church with Princess Eugenie, right, who chose a green dress and co-ordinating jacket Princess Eugenie of York (centre) and Princess Beatrice of York (right) arrive alongside Cressida Bonas, the girlfriend of Prince Harry, for the high society wedding Princess Eugenie of York, Princess Beatrice of York along with Dave Clark were a sea of green and blue as they tottered into the castle in their high heels for the ceremony Support: The Duke of Cambridge and Prince Harry could be seen among the party of dapper gents behind groom Thomas van Straubenzee (left) as he arrived for his wedding today Dressed in their finest: Pippa Middleton, centre, leaves after attending the wedding, accompanied by other glamourous-looking guests Father-to-be Prince William seemed in high spirits as he waved to the crowds and beamed at other guests, while his pregnant wife stayed at home The bride looked ecstatic as she arrived at the church gates and gave enthusiastic hugs to those waiting. Two white horses, with coachmen in all their finery, pulled the historic carriage with Lady Melissa and her father. Chelsy Davy, an official attendant to the bride, wore a pale espresso-coloured dress, and looked delighted to help her friend with the gown and its long train. Despite the Summer date for the wedding, strong winds whipped the light fabric up, making the full gown billow in the breeze. Designer Bruce Oldfield was on hand to make sure it looked perfect. An RAF Search and Rescue Helicopter flies low over Alnwick Castle to 'buzz' the high profile wedding Venue: The couple will marry at St Mary's Church in Alnwick ahead of a lavish reception at the bride's sprawling ancestral home - which has doubled for Hogwarts School in the Harry Potter movies The Duchess of Cambridge's sister and lifestyle writer showed off her slender figure in an elegant peplum dress in muted shades Event: Around 500 guests are expected to attend the society wedding of Thomas Van Straubenzee and Lady Melissa Percy Holly Branson was spring like in a dove-grey and coral combination, while a cheery Tara almer Tomkinson chose a stripey outfit to attend the big day