In Áth Fhada, Gort na hUamha, Co. Thiobraid Árann, a rugadh an staraí eaglasta seo. Deirtear gur chainteoir dúchais Gaeilge é. Laurence freisin a bhí ar a athair. Ba í Catherine Borden a mháthair. Bhí sé i gColáiste Phádraig, Maigh Nuad, ó 1819 amach. Ceapadh é ina dhéan ar an gcoláiste in 1825 nuair a bhí sé ina mhac léinn go fóill i nDún Búinne agus sular oirníodh é. Tar éis dó a bheith ina ollamh le scrioptúr (1827), ina leasuachtarán (1834) agus ina sparánaí (1841) ceapadh ina uachtarán é in 1845. Tá cuntas air ag Patrick Corish in Maynooth College 1795-1995, 1995 agus ag Jeremiah Newman in Maynooth and Victorian Ireland, 1983. Is cosúil nach raibh meas air ag mic léinn. Tugann Newman nóta as dialann an Ard-déagánaigh John O’Sullivan (1806-1874): ‘Renehan was infirmarian when I entered college and as repulsive, forbidding a fellow as needs be. He was evidently in the greatest distress as might be inferred from his patched clothes, mended shoes and darned stockings, a hungry, half-fed, ill-conditioned fellow. With his grey eyes starting from under his thick red eyebrows and his red furry hair standing on end he was about one of the most repulsive characters to be met anywhere.’ Is cosúil go raibh na mic léinn ciaptha aige: ‘The consequence was the whole house was in arms against him. He could not cross the walks or the square without being shouted after and whistled at. His hair was the very colour of the red paint called Raddle with which they mark the sheep and he went by no other name, and however they contrived to procure some of it they did not leave a wall in the house on which they had not written “Raddle” in most conspicuous characters. Even in the refectory they would rise simultaneously as if they were done, that he may say grace, and then sit down again in shouts of laughter at having deceived him.’ Is cosúil nár mhéadaigh caitheamh na mblianta meas Uí Shúilleabháin air. Thug sé cuairt ar an gcoláiste in 1851: ‘Renehan the President became so importunate that I could not refuse staying for the night . . .. Had I not known Larry of old and had I not been convinced of his non-intention to insult, I protest I would have walked out of the room. The Madeira etc satisfied me he did not mean offence . . .. I stood up and moved off to my bedroom. He still followed me, took a chair and made himself at home, argued and crossed and was rude and insolent for near another hour, until I had to turn him out by taking up the chamber pot and saying I could hold out no longer.’
Chuir Denis Brasbie[q.v.] an dlí air toisc drochtuairisce a thug sé d’Easpag Anglacánach Worcester. Bhuaigh Brasbie an cás um Meitheamh 1847 ach níor tugadh dó ach £25 damáiste agus sé phingin costaisí. Bhí caidreamh aige le Seán Ó Donnabháin[q.v.] agus le James Henthorn Todd[q.v.] agus bhí sé ina leasuachtarán ar an Celtic Society agus ina bhall coiste san Irish Archaeological Society. Bhí spéis aige sa cheol eaglasta agus i stair na heaglaise in Éirinn. Scríobh sé: Collections on Irish church history, 2 iml., 1861-73; History of Music, 1858; agus Grammar of Gregorian and Modern Music, 1865.
Bhí an dúspéis aige i lámhscríbhinní. Chaitheadh sé a laethanta saoire á mbailiú. Is lena linn a tháinig bailiúchán luachmhar an Easpaig Seán Ó Murchú[q.v.] chuig an coláiste. Deir Newman: ‘In actual fact, Renehan became an obsessive collector of manuscripts. Alas for the man who gave him the loan of any. One has to suppose that it was only reverential fear of his Archbishop that caused him, in early 1847, to return to Dr Slattery of Cashel five packages of papers which the latter had lent to him. The “Black Book of Limerick”, lent also to him by Bishop Ryan of that diocese, for the purpose of enabling him to write his history of the Archbishops and Bishops of Ireland, fared differently. Renehan still had it when he died and it passed with some of his papers into the library of the College.’ Is dó, in 1848, a scríobh Seosamh Ó Longáin[q.v.] ‘Duanaire na nEascop’ a bhfuil cur síos air ag Pádraig Ó Fiannachta in Clár na Lámhscríbhinn Gaeilge i gColáiste Pádraig Fascúl IV. Deir seisean i bhFascúl VIII: ‘Dealraíonn sé gur fhág sé a lsí go hindíreach ag an gcoláiste; d’fhág sé mar rogha ag na hiontaobhuithe £100, nó “my set of manuscripts known as the O’Renehan MSS together with such other of my manuscripts and rare books illustrative of the history of the Roman Catholic Church in Ireland as the Revd. Dr. Russell of Maynooth College may select, so however that the manuscripts and books as selected by him shall not together with the said O’Renehan M.S.S. exceed in the estimation of the said Revd. Dr Russell the value of two hundred pounds”.’ Deir Ó Fiannachta: ‘De réir an méid a cheannaigh an coláiste ag ceant Uí Reanacháin chuir an coláiste féin breis leis an méid a d’fhág sé chun nithe a cheannach.’ Foilsíodh catalóg na leabhar agus eile a bhí le díol ag an gceant 2 Samhain 1857: Bibliothecha Renehania: catalogue of this rare, valuable and extensive library.
Níor tháinig aon bhiseach ar chúrsaí na Gaeilge sa choláiste lena linn. Deir Uileog de Búrca [B1]: ‘In Maynooth not one student out of a hundred learns, during his course, to spell, to speak, and to write Irish as a language. There is an Irish class but the language of the Gael is treated as the language of the Hebrew race, as something foreign, not the language of thought of the country, of life, of business.’ Is léir nár thug sé aon aird ar easpaig áirithe a bhí ag tathant ar an gcoláiste sagairt le Gaeilge a sheoladh chucu. Bhuail stróc é agus d’éag sé 25 Iúil 1857.