Lucius Septimius Severus was Roman emperor from 193 to 211. Severus was a strong and able ruler. The Roman Empire reached its greatest extent under his reign—over 5 million square kilometres.
New and better-paid army
His policy of an expanded and better-rewarded army was criticised by his contemporaries Cassius Dio and Herodianus.
They pointed out the increasing burden, in the form of taxes and services on the civilian population in order to maintain the new and better-paid army.
The large and ongoing increase in military expenditure caused problems for all of his successors.
To maintain his enlarged military, he debased the Roman currency. Severus’ currency debasement was the largest since the reign of Nero, compromising the long-term strength of the economy.
War against Parthia
In early 197 Severus left Rome and sailed to the east. Soon, he was in Syria.
He immediately gathered his army and crossed the Euphrates. Abgar IX, titular King of Osroene and King Khosrov I of Armenia handed over hostages and assisted Emperor Severus’ expedition.
Severus travelled on to Nisibis to bolster its defense, which previously his general had prevented from falling into Parthian hands. But Severus returned to Syria to plan a more ambitious campaign.
The following year he led another, more successful campaign against the Parthian Empire. His legions sacked the Parthian royal city of Ctesiphon and he annexed the northern half of Mesopotamia.
Severus took the title Parthicus Maximus, following the example of Trajan. However, he was unable to capture the fortress of Hatra, even after two lengthy sieges—just like Trajan, who had tried nearly a century before.
During his time in the east, though, Severus built new fortifications in the Arabian Desert from Basie to Dumatha.
His victory over the Parthian Empire was for a time decisive, securing Nisibis and Singara for the empire and establishing a status quo of Roman dominance in the region until 251 AD.
Invasion of Britain (208 AD)
In 208AD, Severus travelled to Britain with the intention of conquering Caledonia (Northern Britain).
Severus probably arrived in Britain with an army of over 40,000, considering some of the camps constructed during his campaign could house this number.
He strengthened Hadrian’s Wall and reconquered the Southern Uplands up to the Antonine Wall, which was also enhanced.
Severus built a 165-acre (67 ha) camp south of the Antonine Wall at Trimontium, probably assembling his forces there.
Supported and supplied by a strong naval force, Severus then thrust north with his army across the wall into Caledonian territory.
By 210AD, Severus’ campaigning had made significant gains, despite Caledonian guerrilla tactics and purportedly heavy Roman casualties.
The Caledonians sued for peace, which Severus granted on condition they relinquish control of the Central Lowlands.
There is evidence of extensive Severan-era fortifications in the Central Lowlands.
The Caledonians, short on supplies and feeling that their position was desperate, revolted later that year with the Maeatae.
Severus prepared for another protracted campaign within Caledonia. He was now intent on exterminating the Caledonians.
However he died in February 212, and campaign was abandoned by his son and successor caracalla.
Roman Empire reached zenith under him
Though his military expenditure was costly to the empire, Severus was a strong and able ruler.
The Roman Empire reached its greatest extent under his reign—over 5 million square kilometres.
He also enlarged area under the Limes Tripolitanus and secured Africa, the agricultural base of the empire where he was born.
New building & Construction
Severus was also distinguished for his buildings. Apart from the triumphal arch in the Roman Forum carrying his full name, he also built the Septizodium in Rome.
He enriched his native city of Leptis Magna, including commissioning a triumphal arch on the occasion of his visit of 203 AD.