The most famous example of Ethiopian rock-hewn architecture are the 11 monolithic churches of Lalibela, carved out of the red volcanic tuff found around the town. Though later medieval hagiographies attribute all 11 structures to the eponymous king Lalibela (the town was called Roha and Adefa before his reign), new evidence indicates that they may have been built separately over a period of a few centuries, with only a few of the more recent churches having been built under his reign. Archaeologist and Ethiopisant David Phillipson postulates, for instance, that Bete Gebriel-Rufa'el was actually built in the very early medieval period, some time between 600 and 800 AD, originally as a fortress but was later turned into a church.