 After Diocletian's Tetrarchy reform in AD 293, the new "Diocese of Hispania" became one of the four dioceses—governed by a "vicarius"—of the praetorian prefecture of Gaul (also comprising the provinces of Gaul, Germania and Britannia), after the abolition of the imperial Tetrarchs under the Western Emperor (in Rome itself, later Ravenna).The diocese, with capital at Emerita Augusta (modern Mérida), comprised the five peninsular Iberian provinces (Baetica, Gallaecia and Lusitania, each under a governor styled "consularis"; and Carthaginiensis, Tarraconensis, each under a "praeses"), the Insulae Baleares and the North African province of Mauretania Tingitana.Christianity was introduced into Hispania in the 1st century and it became popular in the cities in the 2nd century.