The first Christians met in the private houses of the faithful. Gradually, as local Christian communities became more established both in numbers and in wealth, they might acquire their own church-houses, using them specifically as places of worship and for other religious activities, such as the granting of charity and the instruction of converts. Externally these buildings looked just like other private houses, though internally they might be adapted for their new function, for instance by combining rooms to create a large enough space for worship. The best example of an early church-house is that excavated at Dura-*Europus on the Euphrates: an ordinary town house, built around ce 200, adapted for Christian use before 231, and destroyed when the city walls were reinforced in 257. Before the conversion of Constantine I, and his conquest of the empire between 312 and 324, some Christian communities may already have commissioned halls specifically for worship, and certainly small shrines, such as the 2nd-cent. aedicula over the supposed tomb of St Peter in Rome (see vatican), were already being built over the bodies of the martyrs.