Longfield. English origins in Co. Cork in Southern Munster since the Mid - 17th Century AD.

O Lonnain. They were in the west of Co. Cork in Southern Munster. See O Lennon or O Lenane.

O Looby. See O Luby.

O Loon.  Heremonian Ui Cobhthaigh Ui Felim Dal Cuinn Colla Da Crioch Cenel Rochada Fernmag (Fer Fermaighe) Farney Sept / Family branch, who had their territory at Farney in Co. Monaghan in Southern Ulster in the kingdom of Orghiall / Oriel. Especially see O Loan.

O Loonan or O Loonane - Irish / Ua Luanain / luan (hound or warrior). A Sept / Family branch, who had their territory in Co. Longford in the north - west of Northern Leinster.

Mac Loone. Used as a variant for Mac Glone, which see - Irish /  Mheic Colluin. A Sept / Family branch, who had their territory in the Glenties in Co. Donegal in the north - west of the Ulster Province. Mac Aloon also used there.

Looney. Heremonian Dal Cuinn Colla Da Crioch Sept / Family branch.

O Looney - Irish / Ua Luanaigh. A Sept / Family branch, who had their territory in Co. Clare in the north - west of Thomond / Tuaisceart Mhumhan / Northern Munster  and were also in Co. Cork in Southern Munster. Not connected to Lunney or Lowney.

O Looran or O Loran. Used as variants for O Loughran, which see, in Co. Meath and Co. Westmeath in the south of Northern Leinster.

O Lorcan or O Lorking or O Lorcayne. Heremonian Dal Cuinn Colla Da Crioch Airthir Ui Niallain Clann Cernaich Sept / Family branch, who had their territory at Oneilland East and West in Co. Armagh in the south - east of the Ulster Province and the adjacent country in Co. Monaghan in Southern Ulster where they were  the Chiefs of Farney and West Ui Breasail. Especially see O Larkin.

Lord. Used as a synonym for Kiernan and Tierney, which see - Irish / tighearna (lord).

Lord. English origins in Co. Dublin in the north - east of Southern Leinster and nearby in Co. Westmeath in the south - west of Northern Leinster in the Mid - 17th Century AD.

O Lordan - Irish / Ua Lordain. A Sept / Family branch, who had their territory in the west of Co. Cork in Southern Munster.

Lorimer -

Mac Lorinan. See Mac Larnon.

O Lorkan or O Lorkin. Used as variants for O Larkin, which see. Heberian Dal gCais Sept / Family branch, who had their original territory in Co. Clare in the north - west of Tuaisceart Mhumhain / Thomond / Northern Munster.

O Lorrigan. Used as a variant for O Lonergan, which see.

Mac Loskey. Used as a variant for Mac Cluskey, which see.

Losse -

O Losty - Irish / Ua Loiste. A Sept / Family branch. who had their territory in Co. Donegal in the north - west of the Ulster Province.  O Lasty, O Lastly and O Lusty were used as variants. Leslie also used as a synonym.

Lother or Lowther -

Lough. Scottish toponymic origins used as a variant for Loch, which see. They have been in the Ulster Province since the early 17th Century AD after the confiscation of the 3,500,000 acres of the Heremonian Ui Cobhthaigh Ui Felim Dal Cuinn "northern" Ui Niaill territories by the English and the foreign non - Catholic plantations there.

O Loughan - Irish / Ua Lochain - A Sept / Family branch who were the Chiefs of Gailenga / Gallen in the Barony of Garrycastle in Co. Offaly in the north - west of Southern Leinster.

O Loughan. See O Lohan.

Lougheed. Scottish origins used as a variant for Lochead / head of the loch - akin to Kinloch / ceann an locha - in Gaelic, which see.

O Loughlin or O Loghlin  - Irish / Ua Lochlainn / loch (lake) lann (land) - of the Burren. Gaelic Milesian Irian Sept / Family branch of the Clan na Rory Tuath / Family region. Descended directly from Lochlann a Chief of the Burren in their territory in their kingdom of  Corcomroe in Co. Clare in the north - west of the Munster Province who was descended from the Irian Kings of Ulster who were in turn descended from 37.Ir the Milesian Gaelic Celtic brother who was drowned during the original expedition into Ireland. They were Chiefs of the Burren in the east of Corcomroe  where they had their castle and were kinsmen to the O Connors the Chiefs of Fear Arda and Corcomroe, the O Donnells, the O Baskins, the O Keelys and the O Kellys the Chiefs of Corca Baiscinn and the O Mulcoras there. *62.Rory Mor - the Greater was the Irian 86^th King of Tara / Erinn who died in 218 BC who is the ancestor of the Irian Families from the Clann na Rory and the son of his fifth son was 64.Fergus Mor and his sixth son was the ancestor of 68.Conal Cearnach - of the Victories the leader of the Knights of the Red Branch of Ulster the direct male line ancestor of the O Moores, Mac Guinness, Mac Gowans, and many other important Irian Families in the Ulster Province, the Leinster Province and the Connacht Province. Ancestors: *62 Rory Mor the 86th King of Tara / Ireland (Clann na Rory), 99.Melachlin, 100.Lochlann a youngest brother of 100.Conor the direct male line ancestor of the O Connors of Corcomroe, 102.Awley / Amhailgadh, 103.Melachlin O Loghlin the first to use their surname, 104.Awley, 105.Congalach, 106.Annadh Cam the direct male lone ancestor of the O Hannas / O Hannys / Ui hAnnaidh who had 4 sons 107.Melachlin Cam O Loghlin,  107.Brian, 107.Irial and 107.Donogh the father of 108.Annadh, 109.Rory, 110.Melachlin, 111,Uaithne / Anthony, who died in 1617 AD who had 2 sons, 112.Uaithne and 112.Ros the father of 113.Melachlin who died in 1633 AD, 112.Anthony, 113.Turlogh , 114.Donogh, 115.Turlogh O Loghlin of the Burren 1724 AD.  

O Loughlin - Irish / Ua Lochlainn / loch (lake) lann (land). Heberian Dal gCais Sept / Family branch, who had their original territory in Co. Clare in the north - west of  Tuaisceart Mhumhain  / Thomond / Northern Munster. See also Loughnane. Ancestor: 91.Cas the King of Thomond.(Dal gCais).

Mac Loughlin or O Melaghlin - Irish / Ua Maiolsheachlainn (Descended from a devotee of St. Sechlainn) Heremonian Dal Cuinn "southern" Ui Niaill Clann Cholmain Sept / Family branch, who had their territory in Co. Westmeath in the south - west of Northern Leinster. Ancestor:*107.Malachy 11 / Maol Sechlainn the 40th King of Meath and 174th High King of Ireland who died in 1022 AD. Maol Sechlainn Later corrupted to O Melaghlin, which see, and then Mac Loughlin.

Mac Loughlin or Mac Laughlin or O Loughlin - Irish / Ui and Mac Lochlainn / loch (lake) lann (land). Heremonian Dal Cuinn "northern" Ui Niaill Cenel nEogain Sept / Family branch descended from 105.Ardgar the 44th King of Aileach, a son of 104.Lochlainn, who had their territory at Inishowen in Co. Donegal and in Co. Derry in the north - east of the Ulster Province. They were the most powerful family in Ulster during the Middle Ages, but lost their importance during the 13^th Century AD. Their name is usually anglicized there as Mac Laughlin. Ancestors: *111.Murtough Mac Loughlin / Muirchertach Mheic Lochlainn the 182nd King of Ireland, 110.Niall Mac Loughlin, *109.Donnell O Loughlin / Domhnall Ua Lochlainn  the 179th King of Ireland, 105.Ardgar the 44th King of Ailech, 104.Lochlann,

Mac Loughlin - Irish / Mac Lochlainn / loch (lake) lann (land). Heremonian Dal Cuinn Ui Briuin Sept / Family branch, who had their territory in the Connacht Province where the were kinsmen to the Ui Briuin Ai Septs of the O Connors and Mac Dermots. Ancestors: *89.Eochy Mugmedon the 124th King of Tara / Ireland. 90.Brion the first Dal Cuinn King of Connacht (Ui Briuin), 98.Reilly / Raghallach the 12th King of Connacht (Ui Briuin Ai), 99.Fergus / Muirgius, 100.Murray / Muireadach Muillethan (Ui Muireadhaigh) the 18th King of Connacht,101.Indrechtach the 21st King of Connacht, 102.Murgal, 103.Tommaltach, 104. Muirgius the 31st King of Connacht, 105.Teague / Tadhg Mor, 106.Conor / Conchobar the 38th King of Connacht,

Mac Loughlin or Mac Lachlan - Irish / Mheic Lochlainn, Heremonian Dal Cuinn Colla Da Crioch Siol Daim Argait Ui Cremthainn Clann Lugainn Sept / Family branch of the Maguires who had their territory in Co. Fermanagh in the south - west of the Ulster Province who were kinsmen to the Mac Alears / Mac Eleer / Mheic Gilla Uidhir, Mac Aleese / Mac Gileece / Mac Leece / Mac Illeese / Mac Leese / Mac Lice / Mac Lise etc / Mheic Giolla Iosa, Mac Anally / Mac Cowley / Mac Culloo / Mheic Con Uladh, Mac Auley / Mac Awley / Mac Gawley / Mheic Amhlaoibh. Mac Breen / Mheic Braoin, Mac Caffrey / Mac Godfrey / Mheic Gafraidh, Mac Cassidy / Mheic Asidha, Mac Cormack / Mheic Cormaic, Mac Court / Mac Courtney / Mheic Cuarta / Mheic Cuairt. Mac Corry / Mac Curry / Mac Corrie / Mac Gorry / Mac Godfrey / Mac Gohery / Mac Goffrey / Mheic Gothraidh, O Darragh / O Darra / O Darrough / Oaks / Ui Dubhdhara, Mac Gee / Magee / Mheic Aodh, O Heany / O Heaney or O Heeny / O Heeney / O Hegney / O Henaghan / O Higny / Mac Anenay / Mac Eneany / Bird / Ui hEgneach / Ua hEighnigh / Ua hEicnig. Mac Lilly / Mac Lillie (originally Mac Alilly) Mac Calilly / Mac Lely / Mac Alyly / Mheic Ailghile, Mac Manus / Mheic Maghnuis, Mac Morrow / Mac Murrow / Mheic Murchada (Clann Aodh). Ancestors:  *86.Cairbre Liffeachair the 117th King of Tara / Ireland,  87.Eochy / Echu Doimhlen, 88.Murray / Muireadach Colla Da Crioch / Focrith - of the Two Countries,  89.Rochatha / Rochadh, 90.Dega Duirn, 91.Feicc, 92.Criffan / Crimthann Leith / Lethan, 93.Eochy / Echach,  94.Cairpre Daim Argait, 95.Cormac, 96.Aed, 97.Fergus, 98.Cormac, 99.Eignigh, 100.Irgalach, 101.Lugan, 102.Cearnach, 103.Odhar / Uidhir, 104.Orgiall / Oriel, 105.Serrach, 106.Uidhir, 107.Orgiall / Oriel mac Guire, 108.Searrach Maguire, 109.Odhar Oge Maguire, 110.Randal Maguire, 111.Donn Carrach Maguire the King of Fermanagh,

Mac Loughlin - Irish / Mheic Lochlainn. A Sept / Family branch, who had their territory at Loughlinstown in Co. Dublin in the north - east of Southern Leinster.