William Costelloe Reimagines Paul Costelloe’s Diana-Era Style

At London Fashion Week, the past arrived with broad shoulders, silk scarves and a little more confidence than nostalgia usually allows. William Costelloe’s second collection at the helm of the Irish fashion house looked back to the Eighties vocabulary associated with his late father, Paul Costelloe, while quietly testing what a new generation of the family label might become.

The spring/summer 2027 show opened London Fashion Week on September 17, bringing together familiar Costelloe signatures and a more restrained, contemporary approach to shape. For anyone following lifestyle ireland and Irish fashion internationally, it was a significant moment: an Irish designer’s legacy being carried forward without simply being preserved behind glass.

Lifestyle Ireland meets London Fashion Week

Paul Costelloe’s connection with Diana, Princess of Wales, began in 1983 and continued until her death in 1997. That association helped define one of the most recognisable chapters in the house’s history, with sculpted shoulders, pussy-bow blouses, silk headscarves and polished tailoring becoming part of the label’s visual identity.

William Costelloe did not shy away from those references. The collection included exaggerated shoulders, bow-front shirts, large buttons and headscarves, but the presentation was not a straightforward recreation of royal-era dressing. The designer narrowed the palette to navy, cream and white, with touches of sky blue and butter yellow, allowing the cut and fabric to take centre stage.

That decision marked an important difference between father and son. Where Paul often used vivid colour and expressive prints, William appeared more interested in proportion and construction. Oversized clutches, nautical combinations and unusual trouser shapes gave the collection a modern edge.

Capri trousers, flowing culottes and bubble-hemmed styles reflected fashion’s continuing fascination with shorter or abbreviated lengths. Knitted and tailored hot pants pushed that idea further, while blazers worn over swimsuits and bralettes brought a deliberately irreverent note to the runway.

Some of the more extreme combinations felt less convincing than the simpler tailoring. The most effective looks were often those that allowed one strong idea to carry the outfit: a generous jacket with rounded buttons, or broad shoulders balanced by a clean, contemporary trouser.

That tension was central to the show. William was working within the codes of the Costelloe house, but he was also asking how far those codes could be stretched. It is a question familiar to many Irish family businesses, where tradition can be a foundation without becoming a restriction.

Read more: Explore Irish fashion and lifestyle news in Ireland, from emerging designers to the people shaping modern Irish culture.

Craft, family and a distinctly Irish thread

The change of venue added to the sense of transition. After 15 years at the Waldorf Hilton, the show moved to Banking Hall near Liverpool Street. The setting was different, but the family character remained visible, with William’s sister Jessica Costelloe helping at the entrance and guests including Mollie King and Roxy Horner attending in Paul Costelloe looks.

The show began with a hand-drawn animation by Nicholas Costelloe. A fox travelled through the fabrics and craft traditions of the house, creating an affectionate tribute to Paul and introducing the hand-drawn scarves that appeared later in the collection.

At a time when fashion imagery is increasingly shaped by artificial intelligence, the emphasis on drawing, cloth and visible human workmanship felt particularly relevant. Whether intended as a direct comment on AI or not, the presentation made a clear case for the value of the imperfect, personal mark.

The collection’s Irish identity became most apparent towards the finale. Fabrics from Ferguson’s Irish Linen and Magee were used for appliqué floral dresses, shorts and blazers. These materials connected the London runway to Ireland’s long-standing textile traditions, while the styling kept the result firmly within a modern fashion conversation.

The closing soundtrack, Dolly Parton’s Here You Come Again, added another playful flourish. It reinforced the show’s interest in memory, popular culture and the emotional power of returning to something familiar in a different form.

For readers interested in irish lifestyle, this collection offers more than a seasonal trend report. It shows how Irish design can travel internationally while retaining links to local craftsmanship, family history and a strong sense of place. It also reflects wider ireland lifestyle trends, where heritage, quality materials and individual expression increasingly matter alongside novelty.

Explore more: Discover Irish lifestyle magazine stories about design, culture and modern living from across the country.

What did William Costelloe show at London Fashion Week?

William Costelloe presented Paul Costelloe’s spring/summer 2027 collection, featuring Eighties-inspired tailoring, broad shoulders, pussy-bow blouses, silk headscarves, cropped trousers and Irish textiles.

How was the collection different from Paul Costelloe’s signature style?

William used a more controlled colour palette and fewer prints, placing greater emphasis on silhouette, fabric and unusual proportions rather than colour-led design.

Why was Diana’s influence important to the show?

Paul Costelloe became Diana, Princess of Wales’s personal designer in 1983. The relationship helped establish the house’s association with Eighties tailoring, shoulder pads and feminine bow-front blouses.

William Costelloe’s second collection suggests that the next chapter will not be about abandoning the past. Instead, it will involve deciding which parts of the Costelloe language still speak clearly today. The shoulder pads and pussy bows may belong to Diana’s era, but the sharper restraint, playful proportions and Irish textile focus point towards William’s own direction.

The clearest takeaway for lifestyle ireland is that heritage works best when it remains alive. William has kept one foot in his father’s world while placing the other in a new silhouette—and that balance may become the defining look of Costelloe’s future.