Back in Roman days, as you may know, slavery was part of life. People went to slave markets to buy and sell slaves from all over the known world.

One particular slave market holder became well known for his special promotional contests - people would come from all over the Empire to win one of his slaves.

His most popular contest was a game where you had to try to throw a coin into a Roman urn. If you've seen pictures, you'll know that these urns have very narrow necks, so the game was quite challenging, but if you succeeded, you would win a slave from the market, so the prizes were good.

One day, a fairly poor woman returned from the market with a slave. Her husband immediately berated her for spending so much money to buy a slave, but she told him that she had won the contest, so it had only cost a single penny.

"After all," she said "You've always told me that a penny urned is a penny slaved."