Further laws were introduced, as on 25 May 1566, stipulating that they 'had to abandon the use of Arabic, change their costumes, that their doors must remain open every Friday, and other feast days, and that their baths, public and private, to be torn down.'[44] The reason doors were to be left open so as to determine whether they secretly observed any Islamic festivals.[45] King Philip II of Spain ordered the destruction of all public baths on the grounds of them being relics of infidelity, notorious for their use by Muslims performing their purification rites.[46][47] The possession of books or papers in Arabic was near concrete proof of disobedience with severe reprisals and penalties.[48] On 1 January 1568, Christian priests were ordered to take all Morisco children between the ages of three and fifteen, and place them in schools, where they were forced to learn Castillian and Christian doctrine.[49] All these laws and measures required force to be implemented, and from much earlier.