Grisaille Fleurs de Lys is a series of four autonomous stained glass artworks created by Brian Clarke in 2003. The works feature Clarke's signature motif of the fleur de lys, rendered in free calligraphic lead lines and glazed in clear mouth-blown glass. They are framed within irregular borders of solid lead or coloured glass. Each fleur de lys in this series is adapted to represent a "portrait" of one of Clarke’s friends and collaborators: the architects Jan Kaplický, Oscar Niemeyer, Norman Foster and Zaha Hadid, after whom each work is named.

Speaking about the works in 2021, Clarke said:

"These are part of a quite large group of paintings, drawings, tapestry and stained glass projects and pieces in which I have taken this medieval heraldic symbol and used it as a route map to journey through my own preoccupations and interests. Considering the design perfection of the millennium-old original fleur de lys, my works are like the modern remains or wreckage of ancient masterpieces. I’m involuntarily drawn to the symbol, and it has served me as a metaphor, model and springboard for spontaneity for years."