The Cycle of the Kings
The Cycle of the Kings is the less-defined "fourth" cycle in early Irish literature. It consists of two groups: the tales surrounding King Cormac mac Airt and his ancestors; and the tales of other semi-legendary kings, including those surrounding Niall of the Nine Hostages, the first arguably historical ard righ of Ireland.
Historically, the stories cover a time period from about the year 200 AD to the time of Saint Patrick--roughly 475 AD or so. This is a time of transition in Irish history, moving away from the native Celtic religion towards the introduction of Christianity. We see this in the ways that the gods have fewer and fewer dealings with men; the king who recieves the most attention of the Tuatha de Dannan is Cormac mac Airt, the Arthur-like king who restored Temhair to glory and who was the employer of Fionn mac Cumhaill and his Fianna.
Otherwise, what we see are tales of revenge and murder, but mostly without the supernatural elements of the earlier cycles.
The Stories: