The Glasgow School was a circle of influential artists and designers that began to coalesce in Glasgow, Scotland in the 1870s, and flourished from the 1890s to around 1910. Representative groups included The Four (also known as the Spook School), the Glasgow Girls and the Glasgow Boys. Part of the international Art Nouveau movement, they were responsible for creating the distinctive Glasgow Style (see Modern Style (British Art Nouveau style)). Glasgow experienced an economic boom at the end of the 19th century, resulting in an increase in distinctive contributions to the Art Nouveau movement, particularly in the fields of architecture, interior design and painting. The Four (Spook School) Among the most prominent definers of the Glasgow School collective were The Four. They were the painter and glass artist Margaret MacDonald, acclaimed architect Charles Rennie Mackintosh (MacDonald's husband), MacDonald's sister Frances and Herbert MacNair. Together, The Four defined the Glasgow Style's fusion of influences including the Celtic Revival, the Arts and Crafts Movement, and Japonisme, which found favour throughout the modern art world of continental Europe. The Four, otherwise known as the Spook School, ultimately made a significant impact on the definition of Art Nouveau. The name, Spook School, or Spooky or Ghoul School, was originally a "derisive epithet" given to their work which "distorted and conventionalized human... form." The Glasgow Girls The Glasgow Girls is the name now used for a group of female designers and artists including Margaret and Frances MacDonald, both of whom were members of The Four, Jessie M. King, Annie French, Helen Paxton Brown, Jessie Wylie Newbery, Ann Macbeth, Bessie MacNicol, Norah Neilson Gray, Stansmore Dean, Dorothy Carleton Smyth, Eleanor Allen Moore, De Courcy Lewthwaite Dewar, the silversmith Agnes Banks Harvey and Christian Jane Fergusson. May Wilson and Eliza Bell, among others, continued the tradition of ceramic artistry into the 1940s and 1950s by hand painting various items with floral patterns. Women were able to flourish in Glasgow during a "period of enlightenment" that took place between 1885 and 1920, where women were actively pursuing art careers and the Glasgow School of Art had a significant period of "international visibility". This is sometimes attributed to the "influential" and "progressive" head of the art school, Fra Newbery, who established an environment in which women could flourish, both as students and as teachers. Women benefited from the new Glasgow Society of Lady Artists (founded 1882) which offered a