Lorcáin mac Lachtna also known as Lorcán Locha Deirgdheirc (Lorcán of Lough Derg) or as Lorcán na long (Lorcán of the ships)An Leabhar Muimhneach, Tadhg Ó Donnchadha, page 113, https://archive.org/details/leabharmuimhneac01odon/page/112/mode/2up?view=theater, page 156, https://archive.org/details/leabharmuimhneac01odon/page/104/mode/2up (died 942) was King of the Dál gCais.
Life Reabachán mac Mothla died in 934 and according to the Dál gCais king list in An Leabhar Muimhneach he was succeeded by Lorcáin.An Leabhar Muimhneach, Tadhg Ó Donnchadha, page 323, https://archive.org/details/leabharmuimhneac01odon/page/322/mode/2up The same year of Reabachán's death his son, Duibhghiolla, was murdered treacherously by Lorcáin's son Conghalach. This action presumably allowed Lorcáin and the Uí Toirdhealbhach to seize the kingship from their rivals.Brian Boru and the Battle of Clontarf, Seán Duffy, 2013, page 74
Death According to O'Hart's pedigrees, he died in 942Irish pedigrees; or, The origin and stem of the Irish nation, John O'Hart, page 156, https://archive.org/details/irishpedigreesor_01ohar/page/156/mode/2up and was succeeded by his son Cinnéidigh who made large political strides for the Dál gCais.
Issue Lorcáin had four sons, who all went on to found their own lineages:An Leabhar Muimhneach, Tadhg Ó Donnchadha, page 298, https://archive.org/details/leabharmuimhneac01odon/page/298/mode/2up Cinnéidigh Cosgarach Longargán Conghalach
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