Septimius Severus was Rome's black emperor. Born in the blistering heat of a North African spring in Leptis Magna AD 145, he died in the freezing cold of a northern British winter in York in AD 211. A giant of an emperor, whose career can be counted in superlatives, Severus was in power at the height of Rome's might. He led the largest army to ever campaign in Britain, comprising 50,000 men, part of a Roman military establishment which peaked at 33 legions under his rule. Born into the richest family, in the richest part of the Roman Empire, Severus monumentalised his rule across the empire. He visited - and often fought in - every region. Where he did, he left a mighty legacy in the built environment, for example in Rome where much of the Forum Romanum and most of the imperial palaces are Severan. In North Africa, his hometown of Leptis Magna is all Severan, as are the Roman cities at the Atlas mountains. In London, the land walls that still define the City's Square Mile were delineated under his rule. Visitors to the under croft at York Minster can stand where he died. Septimius Severus was one of the greatest warrior emperors, a hard man who almost died in battle several times and whose attitude is reflected in his deathbed advice to two sons: 'Be of one mind with your family, enrich the soldiers, and despise the rest.'