Mythical early invaders of Ireland, according to the pseudo-history Lebor Gabála [Book of Invasions]; they are named for their leader, Partholón [L Bartholomaeus]. Arriving from the eastern Mediterranean 312 years after the death of Cesair, the leader of the previous invasion, the Partholonians are the first invaders after the Flood and precede the invasion of the Nemedians by thirty years. They often do battle with the predatory Fomorians, nominally the fourth invaders, who prey upon successive inhabitants of Ireland. Under their leader, Cichol Gricenchos, the Fomorians appear hideously misshapen, with only one eye, one arm, and one leg. A beneficent and productive people, the Partholonians clear four plains, form seven lakes, introduce agriculture, and are the first to divide the island into four parts. They also establish the first civilization, fostering law, cauldron-making, crafts, ale-brewing, and hospitality. Their impermanent settlement touches different parts of the island. Landing first at Inber Scéne [Kenmare?] or Donegal Bay at Beltaine time, they settle near Assaroe but later cultivate Mag nElta [Moynalty], the plain between Howth, Clontarf, and Tallaght, coextensive with the modern city of Dublin. After flourishing for 520 years, their numbers reaching 9,000, all the Partholonians die of the plague within one week in May. In a widely known variant text, Tuan mac Cairill survives to the time of Colum Cille to tell the history of the invasions.
Frequently cited Partholonians, after Partholón's family and druids, include: Accasbél, builder of Ireland's first inn or hotel; Babal, a merchant who introduced cattle; Bacorbladra, the first teacher and foster-father; Biobal, a merchant who introduced gold; Breoga, who instructed disputants to settle with a single combat instead of going to war; Feda, the first member to die in Ireland; Malaliach, who first brewed ale, later used in divination, ritual, and sacrifice; Merbán, a champion; Muncnicán, a champion; and Sláine, Ireland's first physician as well as Partholón's son.