"Mausoleum" started as a proper name, of a particular building, for a particular dead man. Mausolus was a 4th-century BCE ruler of Caria, a satrapy of the Persian Empire on the southwestern coast of modern Turkey. When he died in 353 BCE, his widow Artemisia — who was also his sister — commissioned an enormous tomb in the city of Halicarnassus to commemorate him.
A Wonder of the Ancient World
The Mausoleum at Halicarnassus, completed around 350 BCE, was reportedly 45 metres tall, faced with white marble, surrounded by columns and statues, and topped with a stepped pyramid bearing a four-horse chariot. Greek travellers ranked it among the seven wonders of the ancient world. It survived for around sixteen centuries, finally destroyed by a series of earthquakes between the 12th and 15th centuries CE. Stones from the ruined tomb were eventually used by the Knights of St. John to build a castle nearby; some are still visible in its walls.
From One Tomb to All Tombs
Already in classical Latin, the word mausoleum was being used for any especially grand or imposing tomb — a generic term derived from the proper name. The Augustus emperor built his own Mausoleum Augusti on the Field of Mars in Rome, deliberately echoing the original. By the medieval period, the word was a routine architectural term in Latin and survived into the various European languages that descended from it.
A Persistent Habit of Royal Tombs
The Mausoleum at Halicarnassus stands behind a long line of imitations: Augustus's tomb in Rome, the Taj Mahal in Agra (commissioned by Shah Jahan for his wife Mumtaz Mahal), Lenin's mausoleum in Moscow, Grant's Tomb in New York. Each is, etymologically, a tomb after Mausolus — even when the people who built them had forgotten the king himself.