People of Irish origin face a challenging task when they attempt to trace their early roots. The aim of this series is to provide information on ordinary people throughout 17th-century Ireland--with the exception of people of Scottish origin who have been dealt with in Dr. Dobson's "Scots-Irish Links, 1575-1725" series. For Part Four, Dr. Dobson provides sketches of about 1,500 additional inhabitants of Ireland, bringing the grand total so far uncovered in the series to just under 5,000.