Tipping History
Tipping may date back to ancient Rome, where there are indications of money being paid for service above the cost of the service itself. Evidence also exits that in 16th century England patrons would toss coins on the table to attract better service. Another theory holds that European feudal lords threw money to peasants in the streets in insure safe passage.
As for the word "tip", the story goes that before the establishment of a postal service in England, businessmen would give a shilling to the courier "to insure prompt service." Hence, the word "tip".
Above: 16th century english shillings