"The lists of books recorded in Templar inventories show that although many Templar communities possessed only very few books, some had amassed quite substantial libraries. (,,,) None of these book collections were exceptional and if compared with those of established monastic houses even the largest of them seem insignificant. But if one considers that most Templar communities consisted of less than ten professed brothers, of whom few were priests or, for that matter, literate, twenty or more books was a significant enough number to suggest a reasonable demand for, and intense usage of, (mostly liturgical) texts in some Templar houses.
Unlike in the Cistercian Order, where the minimum number of liturgical books for each house was specified in the order’s legislation, the Templars’ acquisition of books was not guided by any official quota or target. Some books had been especially compiled for or commissioned by the Order (...) The Templars received books as donations, entrance gifts or bequests from their own brethren. They also inherited at least some of their books with their churches.
Like those of the Cistercian and other monastic orders, the Templars’ libraries seem, by and large, not to have been the result of systematic or even conscious planning and collecting but the product of necessity and circumstance, reliant as in many cases they seem to have been on the generosity of individual brothers, patrons or their churches’ previous occupiers. (...) How intensively individual Templars occupied themselves with the study of books, which were in any case only accessible to an educated elite within the Order, is therefore difficult to establish. (...)
Among the books discovered in Templar churches (during the trial inventories in 1307-1312, TN) were many psalters, legendaries, martyrologies, and antiphonals, but also books for different offices (officiaria) and breviaries."
Adapted quotes from: The Documentary Evidence for Templar Religion by Jochen Schenk (2017), In: Borchardt, K., Döring, K., Josserand, P. and Nicholson, H. (eds.) The Templars and their Sources. Series: Crusades - Subsidia (10). Routledge, pp. 199-211. ISBN 9781138201903; illustration Old Library, Trinity College – Photo by Swipe/Flickr, source Medievalists.net