Underwood was born in London and studied under Frank Short at the Royal College of Art. He was primarily a sculptor, and founded his own school of art in 1921 in Hammersmith, where his students included Henry Moore, Gertrude Hermes and Blair Hughes-Stanton. Spurning contemporary theories, Underwood believed strongly in the importance of content and meaning, purity and faithfulness to materials, and with Henry Moore, he created a school of sculpture which dominated the 20th century in Britain. He applied these beliefs to all the media he worked in, and his wood engravings had a strong influence on his students. Underwood's linocuts of 1925, 'Human Proclivities', display a true sense of clarity, strength and purity, which emerges again in the lithographs he made in Mexico in the 1930s. Underwood was an experimental printmaker, and some of his work, including the Mexican lithographs, looks ahead to future developments in the art.