His personal library was of enormous proportions. Some accounts speak of him having more than 600,000 books. However, Hitchcock (2014: 91-92) argues that any number in excess of 600 is "inconceivable". The catalogue of library books itself was claimed to be 44 volumes long. According to Hitchcock (ibid.), this may be because "volume" and "page" were confused. Of special importance to Al-Hakam was history, and he himself wrote a history of al-Andalus. Following his death, "Hajib" Almanzor had all "ancient science" books destroyed.