Sir Henry Aaron Isaacs (15 August 1830–2 August 1909) was an Alderman, Sheriff of the City of London and Lord Mayor of London in 1889. Henry ‘Michael’ Isaacs was born in London in 1830, the eldest son of the fruit merchant Michael Isaacs (1802-1859) and Sara née de Mendoza (1793-1859), daughter of Aaron de Mendoza, a relative of Daniel Mendoza, the champion boxer. His nephew was Rufus Isaacs, the first Marquess of Reading. Henry Isaacs was a leading City trader, and, as a Liberal aged 32, he was elected as a Common Councillor in 1862 in the Aldgate ward. He was Alderman in Portsoken from 1883 to 1891 where he took an interest in the markets. He held the office of Sheriff of the City of London between 1886 and 1887 and during 1889-1890 he was Lord Mayor of London. A Freemason, he was Master