Dorothy Isabel Blackham [also known as Dorothy Stewart] was born Dorothea Isabella Blackham in Ranelagh, Co Dublin, Ireland on 1 March 1896. She studied art under Dermod O'Brien at the Royal Hibernian Academy in Dublin from 1916 to 1921, and under Edmund J. Sullivan and Frederick Marriott at Goldsmith College in London in 1921-22. She subsequently returned to Dublin where she worked as a painter, printmaker, linocut artist, lithographer and poster designer. She also attended classes at the Dublin Metropolitan School of Art where she was taught textile design by Sarah A. Reynolds.

She produced numerous prints and cards for the Cuala Press and Cluna Studio in Dublin, and illustrations for the Irish Tourist Association and for magazines, including The Ideal Irish Home and The Bell.

Blackham participated in the Seventh Exhibition of the Arts and Crafts Society of Ireland and Guild of Irish Art-Workers in Dublin in 1925 at which she exhibited graphic art, including lithographed greetings cards, an illustration, a poster, and textile designs. She also exhibited at the Royal Hibernian Academy in Dublin, the Society of Dublin Painters, the Dublin Watercolour Society, the Dublin Painters Society, and the Hugh Lane Municipal Gallery of Modern Art in Dublin; Royal West of England Academy in Bristol; Royal Ulster Academy and Ulster Society of Women Artists in Belfast; and the Royal Academy, the Tempera Society, London Group, and Society of Graphic Art in London. From 1924 she took part in the art exhibitions of the Aonach Tailteann (Tailteann Games) at which she was awarded medals in 1928 and 1932.

During the 1930s she taught art at schools in Dublin and following World War Two was employed by the British Ministry of Health as an art teacher.

In 1944 Blackham served as an assistant warden at the Gibraltarian Evacuation Camp in Derry, Northern Ireland

She married Abraham Frederick Elsner Stewart (1900–1974) in 1947 and from then on exhibited under the name Dorothy Stewart. The couple settled in London where they remained until 1967 when they moved to Donaghadee, Down, Northern Ireland. She died in Donaghadee on 4 September 1975. Memorial exhibitions of her work was held at Queen's University Belfast in 1976 and at The Neptune Gallery in Dublin in 1977.

_{Text source: Art History Research net (AHR net)}