In the mid-thirteenth century, King Jaume I of Arago-Catalonia began to use the captured paper industry of Islamic Játiva to record his reconstruction of conquered Valencia into a multi-ethnic Christian kingdom. His wandering chancery employed local notaries to scribble much abbreviated originals, from which parchments might later be drafted as needed. Over two thousand such registered paper charters on Valencia survive from the last twenty years of Jaume's reign. Their content is multifarious, a kaleidoscope of medieval life: military action, land distributions, personal affairs, religious institutions, pardons of crime, trial transcripts, and the parallel societies of the new kingdom's Muslims and Jews. Hidden among the more amply documented topics are glimpses of life once routine but now rarely encountered in such early records. Among these are passing notices about dogs of war.

Dogs had seen service in the ancient and classical empires, and are deployed today by all the American military services as well as by the CIA, the FBI, and some police departments. Boot camp for military dog recruits is at Lackland Air Force Base in Texas. There has even been a “dog-gate” scandal recently at Camp Pendleton in California where six Marines have been court-martialled and eleven more punished for fiddling with the dogs' personnel files. In history dogs have been used to carry messages, for sentry duty and patrols, to flush out ambushes, to detect explosives, as hunters, trackers, and food tasters, and to break up cavalry charges.