When did Team India win the first Test Series in England?

Source: https://www.aajtak.in/short-videos/video/1971-was-the-first-time-when-india-succeeded-in-winning-the-test-series-by-defeating-the-english-team-on-their-own-soil-this-success-was-achieved-under-the-captaincy-of-ajit-wadekar-2261319-2025-06-11