The Duchess of Edinburgh went back to her '90s roots this week as she showed off an 'effortlessly summery' bob hairstyle.Sophie, 61, who celebrated her daughter Lady Louise Windsor's graduation from St Andrews University yesterday, first revealed her makeover at an agricultural festival in Hertfordshire.Prince Edward's wife, who has been spotted at celebrity stylist Richard Ward's west London salon in the past, had had at least four inches of her tresses cut to a shoulder-grazing length.Adding flair to the 'princess' bob, the feathered ends give the look 'volume and movement' as part of a refreshed look for a 'summer of heatwaves' that is also 'perfect for tiaras', according to celebrity stylist Jay Birmingham.'Whilst tiaras look beautiful with all hair lengths, there are some practical advantages to wearing them with shorter hairstyles,' Jay said, explaining it is much less likely to slip because there isn’t as much weight with short hair.The royal's hair makeover might seem dramatic, considering it is the shortest Sophie has gone in 15 years - but it's hardly her most experimental look.The Duchess has tried different haircuts over the years, sporting everything from pixie cuts reminiscent of Princess Diana's signature look and messy waves to a cropped bob that was even shorter than the one she has now.However, the soft bob is perfect for Sophie, said hair expert Andrew Heasman The Duchess of Edinburgh went back to her '90s roots this week as she showed off an 'effortlessly summery' bob hairstyle The royal's hair makeover might seem dramatic, considering it is the shortest Sophie has gone in 15 years - but it's hardly her most experimental look. Sophie pictured in 1995 The creative director of Rush Hair said: 'Sophie has an oval face shape, which pairs beautifully with this cut, accentuating her high cheekbones and defined jawline. 'The ends have been styled inwards, which adds to the sculptural essence of the look and provides a chic but timeless finish.'Sophie debuted the cut when she visited Hertfordshire for the Groundswell Regenerative Agriculture Festival earlier this week, and attendees were unlikely to miss her new look. Sophie, whose sunglasses were perched on her head, dressed the part in a denim midi skirt with a blue blouse from Penelope Chilvers as she greeted spectators at the 'Glastonbury of farming' in Hitchin. With Britain set to face its third heatwave from Friday, it's understandable why Sophie might want a shorter hairdo as temperatures are expected to soar above 30C again following the hottest May and June days. Sophie finished her look with a pair of tan cowboy boots and simple gold accessories, as she was photographed at Lannock Farm in Weston for the two-day agriculture festival aimed at promoting sustainable farming methods. The last time Sophie went this short was in 2011, when she attended Zara and Mike Tindall's pre-wedding reception aboard the Royal Yacht Britannia in Leith, Edinburgh. Not only is Sophie's new look great for the summer months, it's also 'perfect for a tiara', said Jay Birmingham. 'A bob paired with a tiara also creates a beautifully balanced look, allowing the tiara to remain the focal point rather than being overshadowed by lots of hair. The result is an effortless, elegant, and refined style,' he added. Sophie sported a pixie cut in the early 90s The former PR executive had darker hair in the 90s This hairdo from 2003 was reminiscent of Princess Diana's signature look The last time Sophie went this short was in 2011, when she attended Zara and Mike Tindall's pre-wedding reception aboard the Royal Yacht Britannia in Leith, Edinburgh By 2014, it appeared Sophie was growing her hair out Sophie pictured in 2022 Her new hairstyle was also seen in the official portraits released yesterday to commemorate Lady Louise's graduation from St Andrews University, as Sophie and Edward proudly posed alongside their 22-year-old daughter. While it is not known who is behind Sophie's new look, she has previously been spotted at the Richard Ward salon in West London. Ahead of the King's Coronation in 2023, Sophie was pictured in Chelsea after spending five hours at the hairdresser's, where the average cut and half-head of colour is about £275. The Duchess is far from the only royal who is a client of Richard's.He’s been in charge of Kate’s locks since before her marriage to Prince William (he also styles the rest of the Middleton family), and it is he who masterminded her much-imitated blow-dry.