It would seem that the tradition in Britain goes back several centuries to the time when young boys and girls were sent away from home by their families to work in a trade or to work as a servant for the wealthy.
They would be working away from the village where they had been brought up and it wouldn't be an easy task for them to get home to visit their family. In the build up to Easter these young boys and girls were encouraged by their employer to go home for a short period to see their Mothers and other family members.
It was usual for them to perhaps bring a cake from the kitchen where they worked or a small gift from their workplace. Once they got back home the family would celebrate their child's safe return on what became known as Mothering Sunday. After this the children would return to their workplace and probably not return again until Christmas.
I have tried to ascertain when this 'tradition' became recognisable as the Mothers Day we have today. The earliest newspaper articles I can find which specifically refer to a day called "Mothers Day" are the two below from 1916.
However, an article I found from 1927 suggests the idea didn't really take off as it said :
"It never caught on, mainly because the average Englishman dislikes any parade of sentiment, and partly because it was apparently being exploited by the manufacturers and sellers of suitable presents for mothers."
Today we have blatant exploitation and pressure to spend money on cards and presents which to my mind isn't what Mothers Day should be about. It should be a day when we can just say, as I do,
"Happy Mothers Day Mum, and thank you for everything x"