Before Thatcher, the top tax rate for highest earners was 83%. If it was classed as 'unearned income' (eg capital gains), the tax could have a 15% surcharge, meaning the top tax rate for unearned income was 98%. (Under Thatcher, that went down to 60% - the top rate now is just 45%.)
And people wonder why we suddenly don't have money to fund public services anymore.