As a clan-based society, genealogy was all important. Ireland 'was justly styled a "Nation of Annalists"'. The various branches of Irish learning—including law, poetry, history and genealogy, and medicine—were associated with hereditary learned families. The poetic families included the Uí Dhálaigh (Daly) and the MacGrath. Irish physicians, such as the O'Briens in Munster or the MacCailim Mor in the Western Isles, were renowned in the courts of England, Spain, Portugal and the Low Countries. Learning was not exclusive to the hereditary learned families, however; one such example is Cathal Mac Manus, the 15th century diocesan priest who wrote the "Annals of Ulster". Other learned families included the Mic Aodhagáin and Clann Fhir Bhisigh. It was this latter family which produced Dubhaltach Mac Fhirbhisigh, the 17th century genealogist and compiler of the "Leabhar na nGenealach". (see also Irish medical families).