The Community Charge, popularly dubbed the "poll tax", was a tax to fund local government, instituted in 1989 by the government of Margaret Thatcher. It replaced the rates that were based on the notional rental value of a house. The new tax replaced the rates in Scotland from the start of the 1989/90 financial year and in England and Wales from the start of the 1990/91 financial year. The system was very unpopular since many thought it shifted the tax burden from the rich to the poor, as it was based on the number of occupants living in a house, rather than on the estimated market value of the house.

Mass protests were called by the All Britain Anti-Poll Tax Federation with which the vast majority of local Anti-Poll Tax Unions (APTUs) were affiliated. In Scotland, the APTUs called for mass nonpayment, which rapidly gathered widespread support and spread as far as England and Wales even though no-payment meant that people could be prosecuted. In some areas, 30% of former ratepayers defaulted. While owner-occupiers were easy to tax, nonpayers who regularly changed accommodation were almost impossible to trace. The cost of collecting the tax rose steeply, and its returns fell. Unrest grew and resulted in a number of poll tax riots. The most serious was in a protest at Trafalgar Square, London, on 31 March 1990, of more than 200,000 protesters. Terry Fields, Labour MP for Liverpool Broadgreen, was jailed for 60 days for his refusal to pay the poll tax.

This unrest was a factor in the fall of Thatcher. The Poll Tax was not favoured by Michael Hezeltine, who did not support Thatcher over many of her policies. It was thought at the time that he might become the Conservative party leader, but Thatcher was succeeded by John Major who replaced the Community Charge with the Council Tax, similar to the rating system that preceded the Community Charge. The main differences were that it was levied on capital value rather than notional rental value of a property, and that it had a 25% discount for single-occupancy dwellings.

Extracts from: en.wikipedia.org/wiki/Poll_tax

This carving is well hidden in Shrewsbury, but some locals are aware of it.