William Grindecobbe motivated at least in part to rebel as a result of the pressures of papal taxation. Along with Wat Tyler and John Wrawe, he was one of the key leaders of the peasants during the revolt of 1381, leading the townspeople of St Alban's on 15 June. He was executed in 1381 along with John Wrawe and John Ball. His trial and execution was overseen by Henry le Despenser. During the Peasants' Revolt of 1381, he became well known for his actions against the high lord Thomas de la Mare, Abbot of St. Albans. He led a deputation to King
William Cotton (Lord Mayor) Sheriff of London and Middlesex from 1868 to 1869, and Lord Mayor of London from 1875 to 1876, during which years he opened the new poultry and provisions market at Smithfield and presided over a grand banquet welcoming the Prince of Wales on his return from a tour of India. In 1868 he had stood for parliament unsuccessfully at Southwark. At the 1874 general election he was elected Member of Parliament for City of London. He lost his seat in parliament in the 1885 UK general election after representation was reduced from four to two under the Redistribution of Seats