Harriet Sperling’s mother flew the flag for British fashion on Saturday as she watched her daughter marry Peter Phillips, wearing a bespoke look created by a designer long favoured by royal style icons, including Princess Catherine and Zara Tindall. The mother of the bride, Mary Sanders, turned to luxury British designer Lalage Beaumont, to create her couture-inspired ensemble - and the designer has spoken to the Daily Express exclusively about the milestone moment.

“It was very exciting to be asked to dress Harriet’s mother (Mary Sanders) for this very happy occasion,” Lalage exclusively told the Daily Express. “Having understood that the wedding was to be fairly low-key, I really enjoyed creating an elegant outfit that is both suitable for a beautiful country church and the festivities afterwards.”

The designer also revealed what the brief was for the wedding, which saw Harriet wed Peter in a private ceremony at All Saints Church, Kemble, in Gloucester on Saturday.

Tasked with creating a look that would feel both timeless and practical for a day that stretched from a country church service through to celebrations later in the evening, the designer felt more than capable of the challenge.

The finished ensemble consisted of a bespoke version of the designer’s Vicky coat paired with a matching shift dress underneath.

According to Lalage, the outfit was carefully designed with Mary’s frame and comfort in mind, ensuring she felt confident throughout one of the most important days in her daughter’s life.

“Mrs Sanders is quite petite and wanted a straight style which leant itself to a bespoke version of our Vicky coat and a three quarter length sleeve shift dress underneath,” she explained.

She continued: “The coat is in an exquisite silk-brocade which is woven exclusively for us, with a matching silk sateen dress. For the finishing touches, we added a wonderful cord edging and hand-made frogging at the waist and cuffs to give it a truly unique, couture feel.”

The colour palette was equally considered. Rather than opting for a bold statement shade, the brief focused on creating something elegant and understated that would complement the wider bridal party.

“The brief was to find a colour that would not stand out too much and that would blend with the bridesmaids,” Lalage revealed. The beautiful pewter-grey colour that we selected, we both decided suited her wonderfully, and very much looked the part.”

The dress-and-coat combination has become something of a signature for Lalage Beaumont and remains a popular choice among mothers of the bride looking for an outfit that balances sophistication with practicality.

Explaining the decision behind the silhouette, Lalage said: “We find that many mothers of brides are looking for an outfit of a coat and dress.

“The combination is both practical, (in terms of dealing with what can be quite a long day incorporating possibly a drafty country church, followed by a formal reception and then dancing) and yet also makes them feel special.”

She added: “The classic dress-and-coat combination is a signature of ours because it offers the perfect balance of elegance and practicality. This silhouette ensures the Mother of the Bride looks impeccably tailored and feels entirely comfortable from the morning vows to the final dance.”

The luxury fashion house has become synonymous with timeless occasionwear, couture-inspired tailoring and elegant British craftsmanship. Prior to launching her eponymous label, Lalage honed her expertise at some of fashion’s most prestigious names, including Mulberry - and these experiences have notably helped shape the refined aesthetic for which the brand is now known.

The label has also attracted a loyal royal following over the years. Princess Catherine has notably carried her handbags on a number of occasions, while Zara Tindall was spotted carrying one of the designer’s elegant clutch bags at Cheltenham earlier this year.

For Lalage, being asked to dress the mother of the bride for such a special family occasion was particularly meaningful.

“It is always a pleasure to feel part of such a special day for any family," she said. “To dress the Mother of the Bride for a wedding is incredibly special, and we are thrilled to have played a part in such a happy day.”

Looking back on the finished outfit, however, it was not the couture detailing, luxurious fabrics or bespoke craftsmanship that stood out most to the designer.

Instead, it was something much simpler, she shared, “I just love how well it suits her.”