The collection consists of manuscript material created by Bob Owen, Croesor as well as manuscript material collected by him.
The work of Bob Owen Croesor consists of essays composed for entry in Eisteddfod competitions. These cover a variety of subjects which touch upon local history, Welsh history and Welsh literature e.g. the history of the harp in Wales; emigration from Wales to London; the famous people of Llanfrothen, Merionethshire; the history of the Presaddfed estate, Anglesey; to list but a few. There are also essay notes and lecture notes for Workers Educational Association (WEA) classes, notes made of sermons and notes for radio talks for BBC Radio Cymru.
The numerous letters written by Bob Owen to various correspondents reveal the extent of his knowledge of books and periodicals and Welsh literature - they are full of unique phrases and colloquialisms. A great majority of letters are addressed to Thomas Richards, Librarian of the University College of North Wales. Bob Owen writes of his work in collecting his library, and also of such matters as the war, politics, local history and historical research, Eisteddfodau, BBC radio talks, WEA lectures and Welsh emigration to America.
The collection consists of numerous transcripts made by Bob Owen of parish records and Bishops Transcripts. The records which have been copied cover the following parishes : Betws Gwerful Goch, Dolgellau, Ffestiniog, Llanbedr, Llandanwg, Llandecwyn, Llandrillo-yn-Edeirnion, Llandderfel, Llanddwywe, Llanelltud, Llanenddwyn, Llanfihangel-y-traethau, Tal-y-llyn, Trawsfynydd, Tywyn all in Merionethshire and Aberdaron, Bodfean, Botwnnog, Bryncroes, Cricieth, Dolwyddelan, Llandygwnning, Llangwnnadl, Llaniestyn, Mellteyrn, Penmachno, Treflys in Caernarfonshire and Llanfihangel Glyn Myfyr in Denbighshire.
There are miscellaneous items such as note books and photographs. Items supplied by Bob Owen to the Countryside Exhibits at the Royal Show, Wolverhampton, 1937 as Organiser under the Caernarfonshire Rural Community Council. Also, papers regarding the case between Bob Owen and Crowe's of Wrexham in 1924 regarding the sale of An elegy wrote in a country church yard by Thomas Gray at Sotheby's.
The manuscript material collected by Bob Owen for his library covers a wide range of topics. The poetical manuscripts date as far back as the late 17th century and were composed by many bards e.g. Robin Ddu, Wiliam Phylip, Rhys Goch Eryri, Dafydd Ddu Eryri, Sion Cawrdaf to name but a few. The other literary manuscripts take the form of note books and letters e.g. a scrap book compiled by Myrddin Fardd.
Material of a religious nature includes the accounts of the C.M. Chapel in Bala, Merionethshire,1855-1862 and of Dwyran C.M. Chapel, Anglesey, 1815-1821.
There are diaries and biographies such as the diaries of Evan Evans of Plas Llandecwyn, Merionethshire,1846-1847, and a tour of north Wales, 1830 and a guide to Snowdon from Beddgelert in 1845 by Thomas Jones.
The letters collected by Bob Owen have been divided under the following headings : letters of musicians, letters of famous people, Anglesey matters (from the papers of R.H. Thomas, Pentraeth), letters to Rev. D.D. Williams.
The miscellaneous material includes the accounts of a boatman, the note book of an excise officer, the vestry book, 1830 and other records of Llanfihangel Glyn Myfyr parish, litigation papers regarding the Hendwr estate, Merionethshire and records relating to enclosures and land drainage, roads and transport.