Philip Treacy le Bon, Kate Moss, Christy Turlington and Stella Tennant modelling in return for keeping Treacy's hats, which were all black. In 1994, he opened up his boutique at 69 Elizabeth Street, in Belgravia, London, right beside Isabella Blow's resicence at number 67. Treacy has designed hats for Alexander McQueen (another discovery of Isabella Blow), including his 1999 "white collection" for Givenchy Haute Couture in Paris, for Karl Lagerfeld at Chanel, and for Valentino, Ralph Lauren, Donna Karan, Versace and Rifat Özbek. In January 2000, he became the first milliner for 80 years to be invited to exhibit at the Paris
Noel Treacy the Central Development Committee. The following year he became Minister of State at the Department of the Taoiseach. It was in this capacity that Treacy became the State's first Minister for Heritage Affairs. Between 1989 and 1991 he served as Minister of State for Children at the Department of Health, before being appointed Minister of State at the Department of Justice with responsibility for Law Reform. In 1992 Treacy returned to the Department of Finance again before serving at the Departments of the Taoiseach, Finance, Transport, Energy and Communications during the Fianna Fáil–Labour Party government holding special responsibility for Energy.