In Irish mythology, Fergus (or Fearghus) mac Róich (or mac Róeg) is the former king of Ulster during the events of the Ulster Cycle. He was tricked out of the kingship by Ness, who made her seven-year-old son Conchobar mac Nessa king in his place. Although many of the manuscripts containing texts relating to Irish mythology have failed to survive, and much more material was probably never committed to writing, there is enough remaining to enable the identification of four distinct, if overlapping, cycles: the Mythological Cycle, The Ulster Cycle, the Fenian Cycle and the... The Ulaid, also known as the Ulaidh and the Ulad, are a people of Early Ireland who gave their name to the Irish Province of Ulster. ... Wikipedia does not yet have an article with this exact name. ... In Irish mythology, Conchobar mac Nessa (also Conchobor, Conchubar, Conchobhar, Conchubhar, Conchúr, Conchúir, Conor) was king of Ulster during the events of the Ulster Cycle. ...

After Conchobar's intended bride, Deirdre, had eloped with Naoise, Fergus was sent to offer the fugitive couple safe passage home. However Fergus was waylaid and Conchobar had Naoise and his brothers murdered before forcibly marrying Deirdre. Fergus, outraged by this violation of his word, took his followers into exile in Connacht, where they were taken in by Ailill and Medb. Fergus became Medb's lover, and he and his Ulster exiles fought on her side in the Táin Bó Cúailnge (Cattle Raid of Cooley), against his foster-son Cú Chulainn. Deirdre or Derdriu is the foremost tragic heroine in Irish mythology. ... In Irish mythology, Naoise (also spelled Noise, Noisiu) was the nephew of King Conchobar of Ulster, and a son of Usnech (or Uisliu), in the Ulster Cycle. ... Connaught redirects here. ... In Irish mythology Medb (Medhbh, Maeve) is queen of Connacht during the events of the Ulster Cycle. ... The Táin Bó Cúailnge, or Cattle Raid of Cooley, is the central tale in the Ulster Cycle, one of the four great cycles that make up the surviving corpus of Irish mythology. ... Young Cúchulainn, 1912 illustration by Stephen Reid. ...

Fergus married Flidais, a deer-goddess, and was renowned for his sexual prowess and his enormous phallus (Fergus means "virility"; mac Róich means "son of a great horse"). He wielded the legendary sword, Caladbolg, which he once used to slice off the tops of three hills. He was killed at the instigation of Ailill out of jealousy for his affair with Medb. Wikipedia does not yet have an article with this exact name. ... The phallus usually refers to the male penis, or sex organ. ... In the Ulster Cycle of Irish mythology, the Caladbolg, hard-belly, or Caladcholg, hard-blade, was the sword of Fergus mac Róich. ...