John Grenham came to professional genealogy in 1981, as one of the panel of researchers in the Office of the Chief Herald of Ireland. As in-house researcher for that Office in 1990-91, he was instrumental in setting up the Consultation Service, the forerunner of the current Genealogical Advisory Services in the National Library and National Archives. He was Project Manager with the Irish Genealogical Project from 1991 to 1995. Since 1998, he has run the Irish Times Irish Ancestors website. In 2005, he was the first Genealogist-in-Residence at Dublin City Library and Archive. In 2007, he was awarded a fellowship of The Irish Genealogical Research Society. In 2010, he was awarded a fellowship of The Genealogical Society of Ireland. Among his publications are Tracing your Irish Ancestors (3rd ed.2006), Clans and Families of Ireland (1995), Generations (1996), "The Genealogical Office and its Records" in The Genealogical Office , (1999), Grenham's Irish Surnames (CD-ROM, 2003) and numerous articles and columns in the UK magazine Your Family Tree. He has written the "Irish Roots" column in The Irish Times since February 2009.