Jennifer Finney Boyan explains the English tradition, along with its Irish counterpart:
In England, it’s Boxing Day; in Ireland and elsewhere, it’s St. Stephen’s Day. When I was a student in London, my professor, a Briton, explained that it was called Boxing Day because it’s the day disappointed children punch one another out.
For years I trusted this story, which only proves that there are some people who will believe anything, and I am one of them.
The real origins of Boxing Day go back to feudal times, when workers on a lord’s estate would ask, on this day, for a Christmas box, in exchange for good service throughout the year. Later, the tradition expanded to include the collection of alms for the poor.
In Ireland, St. Stephen’s Day brings the appearance of the Wren Boys— costumed revelers engaged in a ritualized hunting of a wren. The best-known Wren parade happens in Dingle, in County Kerry. There’s a lot of marching around and collecting of money, some of which goes to charity and some of which — according to at least one of my Irish friends — goes to pay for a round at the pub. The veneration of the wren predates Christianity, in fact: The Irish word for wren, “dreoilin” — comes from two words, “draoi ean,” the druid bird.
In London on this Boxing Day, few stores have opened, but at least the Tube has resumed a normal schedule. And, of course, the sun hasn't come out from behind the low overcast all day. Perfect British winter weather.