Historically this was the day when it was expected that Christians in the UK went to visit the ‘mother church’ ie. where they were christened. Later this became a day that domestic servants (particularly young girls ‘in Service’) were given the day off to visit their mothers. Nowadays it has become a more commercial ‘Mother’s Day’ when mothers are remembered, past and present. Although the more recent  Mothers Day is thought to be the American version of the celebration it is held on different dates in the UK and the USA.