Septimius Severus, in full Lucius Septimius Severus Pertinax, Roman emperor from 193 CE to 211 CE.
He founded a personal dynasty and converted the government into a military monarchy.
His reign marks a critical stage in the development of the absolute despotism that characterized the later Roman Empire.
He spent the next six years making major changes in the structure of the imperial government.
Since his power rested on military might rather than constitutional sanction, he gave the army a dominant role in his state.

He won the soldiers’ support by increasing their pay and permitting them to marry.
To prevent the rise of a powerful military rival, he reduced the number of legions under each general’s control.
Severus waged another brief, more successful war in the east against the Parthian Empire, sacking their capital Ctesiphon in 197 and expanding the eastern frontier to the Tigris.
He then enlarged and fortified the Limes Arabicus in Arabia Petraea.
In 202, he campaigned in Africa and Mauretania against the Garamantes, capturing their capital Garama and expanding the Limes Tripolitanus along the southern desert frontier of the empire.
At the same time Severus ignored the Senate, which declined rapidly in power, and he recruited his officials from the equestrian rather than the senatorial order.
Many provincials and peasants received advancement, and the Italian aristocracy lost much of its former influence.
His contemporary saw Septimius Severus as a principal agent in the empire’s decline.
Ordinary people of Rome in the enjoyment of the peace and glory of his reign, forgave the cruelties by which it had been introduced.
Posterity, who experienced the fatal effects of his maxims and example, justly considered him as the principal author of the decline of the Roman empire.
In 209 he invaded Caledonia (Scotland) with an army of 50,000 men but his ambitions were cut short when he fell fatally ill of an infectious disease in late 210.
He died in early 211 at Eboracum (today York, England), and was succeeded by his sons, who were advised by their mother and his powerful widow, Julia Domna, thus founding the Severan dynasty.