Theory:

Sir John Marshall was born on 19th March 1876, in Chester, United Kingdom. He was a prominent scholar who focused on the Indian archaeology scene. John Hubert Marshall invaded into India in 1876, and he stayed here till 1958, he had a very clear, and sweeping.
 
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John Hubert Marshall
Marshall was a talented young man and a gifted archaeologist at such a young age. His primary motivation was to preserve India's ancient heritage.
Marshall had studied Greek at Dulwich College in England and was already a rising star in the region. He went to King'sCollege in England and was awarded the Porzon prize, which was given to someone who could translate Greek verses.
 
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He was a Director-General of the Archaeological Survey of India (ASI) from \(1902\)-\(1928\). He excavated the sites in Harappa and Mohenjodaro. On August \(17\), \(1958\), Sir John Marshall died.
 
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He participated in excavations under the British School's auspices in Athens, where he studied from \(1898\) to \(1901\). He was appointed as director-general of archaeology in India in \(1902\) at the young age of \(25\).
Marshall reorganised the Indian Archaeological Survey and expanded the scope of activity by appointing many Indians. He preserved Indian temples, sculptures, paintings, and other ancient relics that have been forgotten or no longer standing.
John Marshall's enthusiastic efforts in archaeology resulted in preserving ancient buildings all over India during the British rule.
Reference:
https://austria-forum.org/attach/Geography/Asia/Pakistan/Special_Information/Taxila/tax17.jpg
https://upload.wikimedia.org/wikipedia/en/8/80/Sir_John_Marshall.jpg
https://smedia2.intoday.in/indiatoday/images/stories/2017August/arc2-1_081717103406.jpg