Patrick Cremer was born at Greaghnafarna, County Cavan. He trained as a teacher at Marlborough Street, Dublin. He taught in Plymouth and then returned to Ireland to teach in Rockwell College, Cashel. There he met and became a close friend of de Valera. He invented a system of teaching handwriting, the 'Cremer unit system'. By the 1930s the system, in conjunction with 'Cremer Right-Line copy-books', was in use in schools all over Ireland.