The Phoenician Alphabet
Phoenician merchants along the Lebanese coast needed to write quickly, so they used a script of about 22 signs, each standing for a sound rather than a word or syllable. Cuneiform and hieroglyphs required years of training and a professional scribal class; an alphabet could be learned in weeks by an ordinary trader. Carried on Phoenician ships across the Mediterranean, it was adapted by the Greeks, who added vowels, and from them by the Romans. Writing stopped being the property of a priesthood and became something a merchant, a soldier, or eventually anyone could own.
A new way to record or transmit information lowers the cost of copying ideas and reorders who holds knowledge and power.