Twentieth-century painter regarded as the most important Welsh artist of his generation. He is best known for his landscapes, many of which became part of the permanent collection at the Oriel Ynys Mon gallery.
After failing a military physical exam, he began his studies at the Slade School of Fine Art in London, England.
He suffered from epilepsy and, later, lung cancer.
Born to a family of landowners, he lived most of his life on the Welsh island of Anglesey.
He and Australian artist Rolf Harris were contemporaries and friends.