Kate Middleton sends bold message with return of the power suit at surprise visit

The Princess of Wales cut a stylish figure as she joined a group of schoolchildren on a trip to the National Portrait Gallery today. The mother-of-three beamed as she stepped off a minibus with the excited youngsters, holding hands with one little girl as they made their way inside. Kate looked typically chic for the engagement in black pinstripe trousers and a roll neck, teamed with a fitted black blazer. It's a fashion formula that William's wife has come to epitomise.

Long considered one of the world's most stylish women in the world, Kate has undergone a significant shift in recent years. When she first started out on royal life, the Princess relied heavily on floral dresses that were fitted and flared, which she typically teamed with a pair of beige heels. But she now has a new fashion formula, and it's boosted her style credentials even further. The mum-of-three's go-to outfit now typically consists of a beautiful tailored trouser suit, a T-shirt or blouse and pointed court shoes. It's seen as an ideal choice for a modern-day Princess; polished and formal but also relaxed and understated with the addition of a more casual top.

According to a number of experts, the change in Kate's style sends a clear message. "I think it marks a new era in her royal life," Bethan Holt, fashion director at the Daily Telegraph told People magazine. "It shows her confidence is growing and that she's willing to take more risks and do something that might not have come naturally to her.". Bethan continued: "She's transforming before our eyes. She might not be able to say to us, 'Look, my life is now completely different, me and my husband are one step closer to the biggest job of his life,' but she is saying that through her fashion choices.".

Her comments have been echoed by royal style expert Miranda Holder. "Princess Kate's image has definitely taken on a more business-like feel ever since she became the Princess of Wales; her more serious wardrobe reflecting the gravitas of her heavyweight role within the Firm," she told HELLO!. "She has literally been rebranded in line with her new level of authority as the Princess of Wales and her position as our future Queen.".

Notably, Princess Kate is not the only royal to undergo a major style shift at a pivotal time in her life — so too did her late mother-in-law, Princess Diana. "Diana had her own trouser suit moment in the late 1980s at a time when she wanted to be taken more seriously," Holt further added. "She said to designers, 'I'm sick of the frothy ball gowns — I want to wear menswear.' And she had these fabulous power suit moments!".