William Walworth group conspired to keep food prices up, lent money to the king at inflated interest, and through personal and financial influence persuaded the king to issue edicts profitable to themselves. His most famous exploit was his encounter with Wat Tyler during the English peasants' revolt of 1381, in his second term of office as Lord Mayor. In June of that year, when Tyler and his followers entered south London, Walworth defended London Bridge against them. He was with Richard II when he met the insurgents at Smithfield, and killed the rebel leader with his baselard. The circumstances of the killing
Lord Mayor of London been mandatory for election to the Lord Mayoralty. Two Sheriffs are selected annually by Common Hall, which meets on Midsummer's Day for this purpose. By an ordinance of 1435, the Lord Mayor must be chosen from amongst the Aldermen of the City of London. Those on the electoral roll of each of the City's 25 Wards select one Alderman, who formerly held office for life or until resignation. Now each Alderman must submit for re-election at least once in every six years. The Lord Mayor is then sworn in November, on the day before the Lord Mayor's Show ("see below").