Marshall was born in Chester and educated at Cambridge. In 1902 he was appointed Director-General of Archaeology within the British Indian administration, and modernised the approach to archaeology on that continent, introducing a programme of cataloguing and conservation of ancient monuments and artefacts.
It was thanks to him that native Indians were allowed for the first time to participate in excavations in their own country. In 1913, he began the excavations at Taxila, which lasted for twenty years. He then moved on to other sites, including the Buddhist centres of Sanchi and Sarnath. His work revealed to the world the true age of Indian civilisation.