As we get our W2s and 1099s in the mail and realize tax time is coming soon, we get all grumbly about modern taxation. In fact, there have been taxes as long as there have been governments and civilization.
The Roman Empire taxed its provinces, and there was always a great upheaval every year as the provincial governors tried to collect enough money to send to Rome. Early medieval monarchs continued Roman taxation as well as they could, but it tended to fade away by the eighth century.
In Anglo-Saxon England in the ninth century, King Alfred established the Dane geld, a fee of one penny per household, collected to pay off the Vikings. The English had been fighting them and had eventually worked out a treaty, whereby the Vikings stayed in the "Dane law" area (essentially Yorkshire) and would receive an annual payment every year in return for no more raids.
The Dane geld continued even after the Vikings had settled down and intermarried with the English. How much "geld" each village owed was duly noted in the Domesday Book, compiled by the Norman kings of England in the 1080s (ironically, these kings were descended from Vikings, but ones who had settled in France, not England).
England, being an island, was also able to establish import tariffs and the like. But most twelfth-century taxation was centered on cities. The cities that hosted the Champagne trade fairs collected sales tax on every transaction, money used to maintain security.
In the fifteenth century in Florence, the city needed money for security, for wars with other city-states, for judges and street paving and upkeep of the walls and everything else a municipality needs money for. Someone local to each quarter of the city would figure out how every household was doing and, based on his best estimate, issue them an assessment.
But in the 1420s the Florentines decided to make this more rational and logical. They spent a year doing a property assessment for every household in the city--how much furniture they had, how much in municipal bonds, how many spoons, and the like. The resulting catasto is a goldmine for modern historians wanting to learn about life in Renaissance Florence. Based on the catasto, every household was assessed a flat one-half of 1 percent property tax.
More than three-quarters of all resulting assessments ended up being renegotiated. Many of course claimed (with varying degrees of plausibility) that, since the assessors had been around, they'd lost their shirt in an investment, broken a leg and been unable to work, had a fire, and so on, reasons why they couldn't be charged so much. Perhaps surprisingly, many also wanted to pay more. The city had decided that the poorest wouldn't have to pay anything, but the poorest insisted they could scrape up a few pennies at least, because if you didn't pay taxes, you couldn't participate in city government. Florence gave up and went back to their old ad hoc system.
As we pay taxes, it's important to realize what we get in return. If we paid no taxes, we'd have to fight our own wars, catch our own criminals, put out our own fires, teach our own children, pave our own roads, plow those roads ourselves, work out legal disagreements ourselves, determine ourselves if our food and water are safe, take care of the elderly and destitute ourselves, and rebuild unaided from natural disasters. Some of this can in fact be done in very small communities, with everyone working together. But as much as people hate paying taxes, they should realize that government is everybody working together. We disagree a lot on what we need to work on. That's why we're a democracy, so we can vote on what we want.
See more here on medieval taxes.