The Community Charge, more popularly known as the "poll tax", was a tax introduced to fund local government in the UK in the late 1980s. It provided for a single flat-rate per-capita tax on every working adult, at a rate set by the local authority, for example a Billionaire living alone in a mansion would be eligible to pay less poll tax than a whole family living in a small flat. As a result, this increases the power of the wealthy, at the detriment of the masses.
There was mass non payment of the tax around Britain and even a member of parliament was sent to prison for not paying. In 1990 a protest on the poll tax broke out into mass violence in London. The tax was one of the main reasons for the downfall of Margaret Thatcher because the tax was so intensely unpopular. It and was abolished within a few years, in favour of the Council tax, which was a compromise between the Poll tax and the "rates" which the poll tax had replaced, as people with larger houses pay a bit more, but Council tax isn't in proportion to the value of properties and it gives a 25% discount to single occupants, so it is something of a compromise between the Poll tax idea of everyone paying the same and the rates idea of paying a tax linked to the value of your home.
In the United States
In the United States, Poll taxes (Head Taxes) were often imposed as a prerequisite to voting, and were used to limit the political impact of poor Americans.