Milton invented 'pandemonium' as Hell's capital — Greek for 'place of all demons.' It went generic within a century.
Wild and noisy disorder or confusion; uproar; tumult.
Coined by John Milton in 'Paradise Lost' (Book I, 1667) as the name of the capital of Hell — the vast palace where all the demons assemble in council. Milton built the word from Greek 'pan-' (all, every) + 'daimonion' (demon, evil spirit, lesser divine being), on the architectural model of 'Pantheon' (temple of all the gods). The Greek 'daimon' (spirit, divine power) derives from PIE *deh2- (to divide, to distribute — the spirit that distributes fates
Milton coined 'Pandemonium' as the opposite of 'Pantheon.' The Pantheon (pan + theos) was the temple of all the gods; Pandemonium (pan + daimon) was the palace of all the demons. Milton's coinages frequently entered common English — 'sensuous,' 'space' (as the void), and 'earthshaking' are also his inventions.