Eileen Lucy "Tirzah" Garwood (1908–1951), also known under her married name Tirzah Ravilious, was a noted British artist and engraver, considered a member of the Great Bardfield Artists.
She studied at Eastbourne School of Art from 1925, under Reeves Fawkes, Oliver Senior and, as a wood engraver, Eric Ravilious. She later studied at the Central School of Art.
One of Garwood's early woodcuts, shown at the Society of Wood Engravers' annual exhibition in 1927, was praised in The Times.
She undertook commissions for the Kynoch Press and for the BBC, for whom she produced a new rendering of their coat-of-arms. Garwood also illustrated Granville Bantock's oratorio The Pilgrim's Progress, which he wrote as a BBC commission.
In 1930, Garwood married Eric Ravilious. Between 1930 and 1932 the couple lived in Hammersmith, London, where there is a blue plaque on the wall of their house at the corner of Upper Mall and Weltje Road. In 1932 they moved to rural Essex where they initially lodged with Edward Bawden and his wife Charlotte at Great Bardfield.
In 1933 they painted murals at the Midland Hotel in Morecambe.
In 1934 they purchased Bank House at Castle Hedingham, and a blue plaque now commemorates this. They had three children, the first in 1936: John Ravilious; the photographer James Ravilious; and Anne Ullmann, editor of books on her parents and their work. After Anne was born in April 1941, the family moved out of the often cold, and sometimes flooded, Bank House to Ironbridge Farm near Shalford, Essex.
During the winter of 1941 Garwood became ill, was diagnosed with cancer and underwent emergency surgery.
Eric Ravilious died in a plane crash on 2 September 1942, while working on a commission for the War Artists' Advisory Committee.
Garwood began painting in oils and resumed her career. In 1946, Garwood married the Anglo-Irish radio producer Henry Swanzy. However she was again diagnosed with cancer and died in 1952. Her autobiography, Long Live Great Bardfield & Love to You All, was published posthumously, in 2012, after being edited by her daughter Anne.
Two of her paintings are in the Towner Gallery in Eastbourne, which also has the largest collection of Ravilious' work. Both also have works in the Fry Art Gallery.
She was painted by Ravilious, in Two Women in a Garden (1936), alongside Charlotte Bawden.