Nance was born in Cardiff, though both of his parents were Cornish, and he enjoyed holidays with his grandparents in Cornwall from an early age. His brothers were Ernest M (b 1868) and Alwyn (b1870). The family moved to Penarth in 1878 and he developed an interest in the ships both in the docks there and at St Ives. A fine modeller of ships in wood, as well as an accomplished illustrator, producing pencil drawings and oil paintings. A poet and writer, especially of subjects concerning the Cornish language. He began his training at the Cardiff School of Art and in 1893 he enrolled at the Herkomer School of Art at Bushey. He married fellow student Beatrice Michell in 1895, but Bushey rules meant they both had to leave.

He returned to Penarth with his wife and young baby and, on the recommendation of Herkomer, he set up a painting school for a short time. In 1898 he had a poem and illustrations printed in the Cornish Magazine and illustrations reproduced in The Studio. In 1902 his wife died and distraught with grief he decided to immerse himself in further study in Paris for a time.

His titles at this time were Across the Western Ocean (1903), and On the Wings of the Wind (1904). By 1905 he was exhibiting studies of old battleships, some of which were used for decorative screens later exhibited in Italy. In 1906 he married Annie Maud Cawker [See Annie Maud NANCE], a good friend of his first wife and fellow student at Bushey. He was one of the founder members of STISA, but rarely exhibited, and a member of the Arts Club. An acknowledged authority on the Cornish language, he was a member of the Gorseth, becoming Grand Bard of Cornwall in 1934, a position he held until his death. Nance wrote Cledry (1956) and Plays, in addition to an English Cornish Dictionary and a quantity of pamphlets on the Cornish language. A portrait of the artist by Phil Whiting hangs in the St Ives Museum