Original: The following day Domitian was declared emperor by the Praetorian Guard, commencing a reign which lasted fifteen years - longer than any man who had ruled since Tiberius.
Simplified: When Titus died (he was struck down by a fatal illness in 81) the next day Domitian was declared emperor by the Praetorian Guard. This started a reign which lasted fifteen years â "longer than any man who ruled since Tiberius.