A frontier city on the edge of a volcanic plain so fertile it was called 'burnt land,' founded to spread Greek language and culture eastward — hence its name, 'brotherly love.' Devastated by a major earthquake in AD 17 and rebuilt with imperial help; aftershocks were frequent enough that ancient writers describe residents camping outside rather than sleeping indoors. The only other congregation besides Smyrna to receive no complaint at all (Rev 3:7-13): an open door no one can shut, and the promise of becoming a pillar that will never again go out — permanence offered to a city that had just learned how little its own buildings could promise.