My parents are from the West Indies, and they were very strict with me, my Dad never touched me, but used to lecture me a lot and was very strict on going out as a teenager ( all of us went to University and got good jobs, grew up in a poor area) My mum used to beat me at least once a week, with broomsticks, tennis rackets, real abuse. I've forgiven her and she has a wonderful relationship with my DC, who haven't a clue.
I forgave my mother as she told me what her parents did to her back in the Caribbean, which was on another level. My gran once stripped my mother and whipped her with a piece of wire in the street at 14 when she went out partying and came home late when she should of been cooking and cleaning in the house.
Caribbean culture is matriachal where the mother uses beatings for discipline, all of the punishment (abuse) never came out of nowhere, it was for being rude, not doing house work, getting in trouble at school, etc.
Today we call it abuse. The beatings I got as a kid would be grounds for prosecution , and me getting taken into care today, the beatings my mother got would be grounds for imprisonment!
As a family we have all moved on, I forgive my mother and because she has forgiven my gran, so have I.
It was wrong, evil even, but it belonged to an old culture of voilence, Trinidad's voilent slave history and common ideas about spare the rod and spoil the child- an old English saying, remember we only banned corporal punishment in schools in 1986 here! Corporal punishment is still legal in many Caribbean schools, but that's the case still in 19 states in America, lets not forget.
Move on and forgive your gran if your Dad has. She misguidely thought she was doing the right thing.