It's another travesty of the so called British justice system. The four who were wrongfully imprisoned were Paul Hill, Gerry Conlon, Paddy Armstrong and Carole Richardson.
PS A reminder for the Corbyn naysayers on here.
'Jeremy Corbyn was one of the early supporters of Hill and the others wrongly convicted of the 1974 Guildford bombing UK politician Jeremy Corbyn is featured in “never before seen” photos from Guildford Four Paul Hill’s 1988 wedding while he was in prison after being wrongly convicted of an IRA bombing in London.' https://www.irishcentral.com/news/jeremy-corbyn-paul-hill-guildford-four
'The Guildford Four were falsely convicted of the bombings in October 1975 and sentenced to life in prison. The Maguire Seven were falsely convicted of providing bomb-making material and other support in March 1976 and sentenced to terms varying between four and fourteen years.'