The census of 1851 was the first to record place of birth, marital status and occupation for people living in Britain. The census that year also recorded a jump in London’s Irish-born population from 75,000 in 1841 to 109,000 in 1851, reflecting mass migration caused by An Gorta Mór, Ireland’s Great Famine of 1847-1852. While London’s Irish population had long been concentrated in poor central districts like Whitechapel and St Giles in the Fields, a small minority lived in Hackney and Stoke Newington. And their census records - as workers, wives, clergy and institutional inmates - illuminate less familiar aspects of the Irish presence in Victorian London.