School Master (1958) - a masterpiece in Kannada by B.R.Panthulu School Master (1959) - remade by Panthulu himself in Hindi Zindagi (1976) - Starring Sanjeev Kumar and Mala Sinha
I believe there is at least one version each in Telugu (late 50s or 60s), Tamil (60s) and Malayalam (70s?).
It would be a worthwhile exercise to see the changing social context depending on when this story has been filmed. IMO, the 1958 version is a must-see.