According to Gaelic traditional history, laid out in works such as the Book of Invasions, the earliest king of Munster was Bodb Derg of the Tuatha Dé Danann.

From the Gaelic peoples, an Érainn kindred known as the Dáirine (also known as Corcu Loígde and represented today in seniority by the Ó hEidirsceoil) provided several early monarchs including Cú Roí.

Their hold was loosened by the rise of Brian Bóruma of the Dál gCais, who established the Ó Briain as kings of Munster.

There were a number of Gaelic attempts to reassert their power in Munster, such as that of Fínghin Mac Cárthaigh and Domhnall Cam Ó Súilleabháin Bhéara, but these were not successful.

There were not verifiable Eóganacht overkings of (all or most of) Munster until the early 7th century, after the Corcu Loígde had fallen entirely from power, some time after losing their grip on the Kingdom of Osraige and the support of the Muscraige and others.