The Dagda is a father-figure and protector of the tribe. He is also known as "All-father", and "lord of great knowledge". He was a beautiful god of the heathens, for the Tuatha Dé Danann worshipped him. He was an earth-god to them because of the greatness of his (magical) power. In some texts his father is Elatha, in others his mother is Ethniu. His siblings include the gods Ogma and Lir.
He was known to possess immense power; armed with a magic club and associated with a cauldron. With this club he was able to kill nine men with one blow; but with the handle he could return the slain to life. The cauldron was known as the "Undry" and was said to be bottomless, from which no man left unsatisfied. Uaithne, also known as "the Four Angled Music", was a richly ornamented magic harp made of oak which, when the Dagda played it, put the seasons in their correct order; other accounts tell of it being used to command the order of battle. He also possessed two pigs, one of which was always growing while the other was always roasting, and ever-laden fruit trees.
The Dagda was a High King of the Tuatha Dé Danann after his predecessor Nuada was injured in battle. The Tuatha Dé Danann are the race of supernatural beings who conquered the Fomorians, who inhabited Ireland previously, prior to the coming of the Milesians. His lover was Boann and his daughter was Breg. Prior to the battle with the Fomorians, he coupled with the goddess of war, the Mórrígan, on Samhain in exchange for a plan of battle.
The Dagda had an affair with Bóand, wife of Elcmar. In order to hide their affair, Dagda made the sun stand still for nine months; therefore their son, Aengus, was conceived, gestated and born in one day. He, along with Bóand, helped Aengus search for his love.
The Dagda was also the father of Bodb Dearg, Cermait, Midir, Aine, and Brigit. He was the brother or father of Oghma, who is probably related to the Gaulish god Ogmios; Ogmios, depicted as an old man with a club, is one of the closest Gaulish parallels to the Dagda. Another Gaulish god who may be related to the Dagda is Sucellus, the striker, depicted with a hammer and cup.
He is credited with a seventy or eighty-year reign (depending on source) over the Tuatha Dé Danann, before dying at the Brú na Bóinne, finally succumbing to a wound inflicted by Cethlenn during the second battle of Magh Tuiredh.