In the ancient days, it was common for a bell to be placed in the center of a town or fief. This bell was hung for anyone to ring who had received a great wrong. Once rung, a lord would call together the wise men or druids appointed for this purpose, in order that justice might be done.
A particular town, whose name has long been lost to history, had such a bell. However, the bell had been used so long that the rope had wasted. Rather than using another rope, a vine was tied to it.
Now it befell that a knight in the town had a noble charger which had grown old, so that it had lost its worth. The knight, to avoid the expense of its keep, let it wander about. The famished horse, being left to its own devices, tugged at the vine to eat it. As it tugged, the bell rang.
The judges assembled, and understood the petition of the horse who, it seemed, asked for justice. They sentenced that the knight, whom the horse had served when it was young, should feed it now that it was old.