axes, and agricultural implements rendered the Celts militarily superior to their neighbours, and they were able to open roadways through the previously impenetrable forests of Europe. An ancient Irish word for road, still in use today, is slighe, from the word sligim, “I hew.” The very word iron is derived from the Celtic iarn, spreading from that source into most European languages via Latin. Iron bars of certain weight were sometimes used in ancient Celtic society as currency. In the story of the Táin, Ailill and Medb, counting their treasures, list iarn-lestair, or “iron vessels.” Sliabh an Iairinn (Mountain of Iron), east of Lough Allen, Co. Leitrim, was where Gobhniu, the smith god, worked. In the story of Matholwch’s attempt to obtain the magic cauldron from Llassar Llaesgyfnewid and Cymidei Cymeinfoll, Matholwch builds a house of iron in which to destroy these two, who are obviously deities of death and battle.

Irusan

[I] A monstrous cat that dwelt in a cave near Knowth on the Boyne. It is said to have seized the chief bard of Ireland, Seanchán Torpéist, in its jaws and to have run off with him.

Ith

[I] Son of Bregon. He is said to have dwelt in a great tower that his father had built in Spain (the Irish synonym of the “Land of the Dead”). From this tower, Ith saw Ireland and embarked with 90 followers. They landed at Corca Duibhne (Corkaguiny, Co. Kerry). The Dé Danaan had just defeated the Fomorii at the second Battle of Magh Tuireadh and Nuada had been killed. Mac Cécht, Mac Cuill, and Mac Gréine were attempting to divide Ireland between them. Ith was asked to make a judgment on how this should be done. His panegyric was interpreted as an indication he wanted to rule Ireland himself. The Dé Danaan killed him. His body was taken back to Spain, where his children resolved to take vengeance by conquering Ireland; thus began the Milesian invasion.

Iubdan

[I] King of the Faylinn, a kingdom of diminutive people. His wife was Bebo. Iubdan was a constant boaster and to quell the boasting his poet Eisirt told him that Ulster was a land of giants. To prove it he went there and returned with Aedh, dwarf of the Ulster king Fergus Mac Léide. Eisirt then placed a geis on Iubdan to go to Ulster and be the first to taste the porridge of the king on the next morning. Iubdan and Bebo go to Ulster, but they fall in the porridge and are made prisoners. Fergus falls in love with Bebo and has an affair with her. After a year and a day, Fergus offers to free them