Greaves was admitted to Charterhouse as a Poor Brother in 1922 at the age of 76.
He and his brother Henry both self-taught under the sway of Whistler. They acted as his studio assistants and rowed him along the river. In the late 1870s, he was rejected by Whistler and suffered penury and neglect for many years until a brief respite in 1911 with One Man show at the Goupil Gallery. In 1922, the Artists' General Benevolent Fund arranged for his admittance to the Charterhouse.