Hugh MacDiarmid is the pen name of Christopher Murray Grieve (11 August 1892 – 9 September 1978), a significant Scottish poet of the 20th century. He was instrumental in creating a Scottish version of modernism and was a leading light in the Scottish Renaissance of the 20th century. Unusually for a first generation modernist, he was a communist; unusually for a communist, however, he was a committed Scottish nationalist. He wrote both in English and in literary Scots (often referred to as Lallans). MacDiarmid was born in Langholm. After leaving school in 1910, he worked as a journalist for five years. He then served in the Royal Army Medical Corps during the First World War. After the war, he married and returned to journalism. His first book, Annals of the Five Senses (1923) was a mixture of prose and poetry in English, but he then turned to Scots for a series of books, culminating in what is probably his best known work, the book-length A Drunk Man Looks at the Thistle. This poem is widely regarded as one of the most important long poems in 20th-century Scottish literature. After that, he published several books containing poems in both English and Scots.
In 1928, MacDiarmid helped found the National Party of Scotland. He was also a member of the Communist Party of Great Britain. During the 1930s, he was expelled from the former for being a communist and from the latter for being a nationalist. From 1931, whilst he was in London, until 1943, after he had left the Shetland island of Whalsay for conscripted war work in Glasgow, MacDiarmid was watched by the British Intelligence Services. In 1949, George Orwell compiled a list of suspected communist sympathisers for British intelligence. He included MacDiarmid in this list. In 1956, MacDiarmid rejoined the Communist Party.