Chamber and camera share the same ancestor, though they look nothing alike today. Greek kamara described a room with an arched or vaulted ceiling — the kind of solid stone construction common in Mediterranean architecture. Latin borrowed it as camera, keeping the architectural sense but extending it to mean a treasury or vault (because valuables were stored in secure arched rooms). Old French transformed camera into chambre through regular sound changes: the Latin c before a became ch in French, and the vowel shifted. English adopted chambre in the 13th century for a lord's private quarters in a castle, the most intimate room in the household. The word's association with privacy explains why it later attached to legislative assemblies meeting behind closed doors — a chamber of parliament is, at root, a private room for deliberation. Meanwhile, the untransformed Latin camera survived in Italian, giving us camera obscura ('dark room') and eventually the photographic device. The same Greek vault produced the English bedroom and the device in your pocket.