Liamuin is a poem in Dindsenchas ÃÂrann which explains the medieval Irish place-lore relating to nine assemblies and noted places in Ireland. The premise is largely dedicated to the etymological legend for Lyons, a hill and former royal inauguration site. Lyons, on the border between the modern counties of County Kildare and County Dublin was later the focus of a parish; it is situated near the banks of the River Liffey, 20 km upstream from Dublin.
The section of Dindsenchas ÃÂrann containing this poem is found in the 12th-century Book of Leinster and was probably composed by Cináed Ua Hartacáin (d. 975). The legends mixed real and fictional events and people to create place legends for the names of about 300 locations in Ireland. Place names are explained by reference to legends which are linked to them by means of pseudo-etymological techniques, where sometimes fictitious stories are adduced to explain the existing names, with the result that some of these legends are only to be found in the Dindshenchas, where they serve their explanatory purpose. The Dindsenchas reflect a mentality in which the land of Ireland is perceived as being completely translated into story: each place has a history which is continuously retold. The expressed mentality of Dindsenchas is to be found throughout all phases of Irish literature. It was part of the body of knowledge medieval Irish poets were expected to master, and the importance attached to the material is reflected in its presence in many of the major manuscripts.
They are not to be taken literally. For example, Dublin, a name derived from the Irish name Dubh Linn, literally the "black pool" where the Dodder meets the Liffey, is re-imagined through the guise of an elaborate legend about a princess who died at the spot where Dublin was built. Instead it reflects the literary, religious and political hierarchies of the time. During a period of the North Kildare dynasty, the UàDúnchada branch of the UàDúnlainge kindred were at their most powerful, and supplied ten kings of Leinster from their base on nearby Lyons Hill between 750 and 1050. In choosing Cnoch Liamhna for mention as one of the "assemblies and noted places in Ireland," the poem is an indication of the strength of the local ruling family, It also includes a separate place legend for nearby Straffan. Unlike Liamuin, Lumman Tige Srafáin is a work of prose and not part of the metrical Dindsenchas.
The explanation for Lyons is that Liamhain is Irish for elm tree.