Giles Fraser writes wonderfully in The Guardian on parish boundaries and the ancient English (and Welsh) tradition of beating the bounds:
In a world before maps and title deeds, clarity about boundaries was passed down through memory. Young people would take sticks and bash out various important intersections, shouting “mark, mark, mark”. Sometimes, as a way of helping them commit places to memory, the youngsters would be whipped at various key junctions. Their cries would then be bought off with money.
In some parishes they still continue to beat the bounds. In the parish of St Mary the Virgin, Oxford, they collectively perambulate through some otherwise private bits of the university colleges, even through a college kitchen, so as to reassert the ancient boundary. At All Hallows by the Tower, in the City of London, they recreate a riot that took place in 1698 between the parish and the Tower over what bit of land belonged to whom.
Here is film of the beating of the bounds in various London parishes in the 1920s, via British Pathé:
The parish, it seems, is the perfect size for a successful moral community. And that’s why the beating of the bounds had a hidden moral purpose. For historically, one of the practical purposes of clarity about parish boundaries was that they determined who was responsible for looking after whom. For well over 200 years, between the dissolution of the monasteries and the Industrial Revolution, successive poor laws made the local parish responsible for its destitute members. The community was obliged to look after its own. It was the parish that organised the building of almshouses and the raising of local taxes to support the poor. This system survived until the great reforms of 1832, after which the poor had to go into a workhouse to find support. With industrialisation, and the globalisation that followed in its wake, the link between the relief of poverty and the local community was broken.