How did Septimius Severus die

In 209, Septimius Severus invaded Caledonia (modern Scotland) with an army of 50,000 men.
He prepared for a long campaign within Caledonia. He intended on exterminating the Caledonians resistance and making it a Roman province.
Severus’ campaign was cut short when he fell ill. He withdrew to Eboracum (York).
Before his death, Severus famously gave advice to his sons: “Be harmonious, enrich the soldiers, scorn all others”. Soon, he died on 4 February 211 AD.
Although his son Caracalla continued campaigning against caledonia. The following year, he soon settled for peace.
On his death, Severus was deified by the Senate. On the advice of Severus’ wife Julia Domna, his sons, Caracalla and Geta, became the joint emperor.
Severus was buried in the Mausoleum of Hadrian in Rome. His remains are now lost.

Septimius Severus Grave

After his death in 211 AD, Severus was buried in the Mausoleum of Hadrian in Rome. His remains are now lost.

The urns containing his ashes were probably placed in the Treasury Room, deep within the building.
In 401 AD, the contents of his tomb and decoration were lost and the building was converted to a military fortress.
His tomb was subsequently included in the Aurelian Walls built by Flavius Honorius Augustus.
The urns and ashes were scattered by Visigoth looters during Alaric’s sacking of Rome in 410 AD.
Later attacking Goths destroyed the original decorative bronze and stone statuary when they besieged Rome in 537