When Arthur Guinness used a £100 legacy to set up a brewery in Ireland’s County Kildare in 1755, he could not have anticipated that his liquid assets would create one of the wealthiest families in the British Isles.

Family wealth translated into political power. Sir Benjamin Guinness, Arthur’s grandson, became Lord Mayor of Dublin and the city’s MP, as well as running the brewery and introducing the harp logo. His son, Edward Cecil, secured both the business and the family legacy. He floated Guinness in London, became high sheriff of Dublin, a baron, viscount and earl, chancellor of Dublin University and the richest man in Ireland. As the first Earl of Iveagh he created the Guinness Trust, one of the biggest housing associations in Britain. The family continued as major shareholders at the brewer for another 80 years, but became less and less involved.