He became a Benedictine monk at the Gorze Abbey in 933 after renouncing his wealth as an administrator of landed estates and making a pilgrimage to Rome and Monte Cassino.
Having found no monastery with a strict enough discipline, John had formed relationships with like-minded men, such as Einald, formerly archdeacon of Toul.
In 933, Bishop Adelbero of Metz [fr] (929-962) had asked John and Einald to restore and reform the decayed monastery of Gorze.
He is reputed to have had a photographic memory, and also developed a bookkeeping system and capital investment policies[4] It was claimed that the murmur of his lips reading the Psalms resembled the buzzing of a bee.
The caliph, fearing that the letter of the German emperor might contain matter derogatory to Islam, commissioned Hasdai to open the negotiations with the envoys.
John of Gorze said that he had "never seen a man of such subtle intellect as the Jew Hasdeu" [7] An English translation of his account is published as ‘Niceties of diplomacy (953-56)', in Christians and Moors in Spain, trans.