Robert Morton Nance was born in 1873 in Cardiff of Cornish parents. He studied art at Bushey, Hertfordshire under Sir Hubert von Herkomer and later in France and was a skilled painter. Nance moved to Cornwall in 1906 and lived at Nancledra near St Ives. He was a founder of the Society for Nautical Research in 1911 and an authority on maritime art and history. His book “Sailing Ship Models” was published in 1924.
Nance became a leading authority on the Cornish language, and was also a joint founder of the Old Cornwall Society. He wrote numerous books and pamphlets on the language, including a Cornish dictionary, which became a standard work. He also edited the journal of the Federation of Old Cornwall Societies. He was involved in the first Cornish Gorseth in 1928, following attendance at the Breton Gorseth during the previous year.
During the early part of the 20th century, Robert Morton Nance wrote the Cledry plays. These plays were intended to carry on the West Penwith tradition of turning local folk tales into plays, particularly for acting at Christmas.
The foundations of Unified Cornish were laid by Henry Jenner, who published his "Handbook of the Cornish Language" in 1904. This was based upon Cornish as it was used as a living language in the 14th and 15th centuries. Nance built upon this and produced “Cornish for All” in 1929. This was followed in 1938 by his dictionary which, with various revisions, is still in use today. An alternative version of the language, known as Common Cornish, was developed by a different group in the 1980s.