Marcus King longed for a career in the arts from a very early age. At fifteen, he was awarded a junior cadetship in the architectural division of the Public Works Department at Wellington. A job transfer to Auckland in 1906 provided him with the opportunity to attend evening classes at Elam School of Art under the renowned painter Edward Fristrom.
King and Fristrom developed a strong friendship and often went on sketching trips together. Upon his return to Wellington in 1916, King exhibited at the New Zealand Academy of Fine Arts. With the following year came the First World War and King joined the army.
Upon his return from the war, King began work in the advertising industry as a commercial artist, as well as teaching art at the Wellington Technical Institute.
King maintained his association with the Academy of Fine Arts, serving on the council from 1929-1941. He was listed as an exhibitor up until 1964.
The Wellington City Council recognised King as an established painter and commissioned him to paint the city and its harbour, as a gift to Lord Freyburg upon the completion of his term as Governor General.
A further commission saw his work on display in the Scott Base in the Antarctic.
King's works are held in the collections of the Auckland City Art Gallery, Dowse Art Museum, Hocken Library, Robert McDougall Art Gallery, Rotorua Museum, Sarjeant Gallery, Suter Art Gallery, Museum of New Zealand Te Papa, Alexander Turnbull Library and the Whangerei Museum.