Describe the contribution of John Marshall, Director-General of the A.S.I. to Indian archaeology.
Before discussing John Marshall's work we should discuss the general picture of archaeology in India of that time. Most of the archaeologist prior to Marshall was of view that indian civilization started from 6th century BCE and there was this tendency to use written words to guide the archaeological digs. Thus when Cunnigham came across with Harappan artefacts he was not able to understand it and tried very hard to fit it within the time frame he was familiar with (6th - 4th century BCE).
It was much later when Daya Ram Sahni discovered seals which he found in the layer of soil which was way more older than the 6th century BCE. The information began to come and it was Rakhal Das Bannerji who discoverd the similarities of the seals discovered from the various sites leading to the conjecture that these sites were part of a single archaeological culture. Based on these finds, in 1924, John Marshall, Dir ector General of the ASI, announced the discovery of a new civilisation in the Indus valley to the world. It was then that the world knew not only of a new civilisation, but also of one contemporaneous with Mesopotamia.
However it was also during Marshall's stints as Director General that lots of context in which artefacts were discovered were lost becuase he ignored the stratigraphy of soil, the mistake which was noted by Wheeler ( next director general). Even then it was during his tenure that Indians were allowed to participate in excavations in their own country. And as S N Roy has said “Marshall left India three thousand years older than he had found her.”