In construction

The outline below is an interim measure, taken from Wikipedia

Septimius Severus (193–211 AD)

Lucius Septimius Severus

Born in Leptis Magna, in the Roman province of Africa proconsularis

He rose through military service to consular rank under the later Antonines.

Proclaimed emperor in 193 AD  by his legionaries in Noricum during the political unrest that followed the death of Commodus, he secured sole rule over the empire in 197 AD, after defeating his last rival, Clodius Albinus, at the Battle of Lugdunum.

Severus fought a successful war against the Parthians and campaigned with success against barbarian incursions in Roman Britain, rebuilding Hadrian's Wall.

In Rome, his relations with the Senate were poor, but he was popular with the commoners, as with his soldiers, whose salary he raised.

His Praetorian prefect, Gaius Fulvius Plautianus became influential from ca. 197 but was executed in 205 AD. 

Severus died while campaigning in Britain.

He was succeeded by his sons Caracalla (the older) and Geta, who reigned under the influence of their mother, Julia Domna.

Caracalla (198–217 AD)

Lucius Septimius Bassianus

Born in Lugdunum, Gaul.

‘Caracalla’ was a nickname referring to the Gallic hooded tunic he habitually wore even when he slept.

Upon his father's death, Caracalla was proclaimed co-emperor with his brother Geta.

Conflict between the two culminated in the assassination of the latter.

Reigning alone, Caracalla was noted for lavish bribes to the legionaries and unprecedented cruelty, authorising numerous assassinations of perceived enemies and rivals.

He campaigned with indifferent success against the Alamanni.

The Baths of Caracalla in Rome are the most enduring monument of his rule.

He was assassinated by a Praetorian Guard while en route to campaign against the Parthians.

Geta (209–211 AD)

Publius Septimius Geta

Geta was made co-emperor with his older brother Caracalla upon his father's death.

They were famously hostile to each other.

Geta was assassinated in his mother's apartments by order of Caracalla, who thereafter ruled as sole Augustus.

[Macrinus (217–218 AD)]

M.M. Opelius Macrinus

Although not part of the Severan dynasty, he rose through the imperial household.

He became Prefect of the Praetorian Guard under Caracalla.

Macrinus became involved in a conspiracy to assassinate Caracalla [above] and was declared Augustus three days after the deed was done.

He made peace with the Parthians on what many thoughtwere degradingterms.

However also failed to award the pay and privileges promised to the eastern troops that had been promised by Caracalla.

His army in Syria became attracted to the young Elagabalus [below].

Macrinus and Elagabalus joined battle near Antioch.

Macrinus was defeated and escaped to Chalcedon, where he was betrayed and executed.

Elagabalus (218–222 AD)

Varius Avitus Bassianus on May 16, 205 AD, he became known later as M. Aurelius Antonius

He was also known as "Elagabalus," from the Latin name for the Syrian sun God Heliogabalus, of whom he had become a priest at an early age.

Elagbalus was proclaimed Emperor by the troops of Emesa, his hometown, possibly at the instigation of grandmother, Julia Maesa. She spread a rumor that Elagabalus was the secret son of Caracalla.

Elagabalus was soon accepted as Augustus by the Senate, and began the slow journey to Rome.

The literary sources stress his debauchery, probably embellishing the facts.

His grandmother, Julia Maesa and mother, Julia Soamias were both influential during his reign.

Julia Maesa persuaded Elagabalus to accept his cousin Alexander Severus [below] as Caesar but Elagabalus, jealous of this popularity, removed the title.

Elagabalus and his mother were murdered in a Praetorian Guard camp mutiny.

Alexander Severus (222–235 AD)

Marcus Julius Gessius Bassianus Alexianus

Alexander was made Caesar by his slightly older and very unpopular cousin, Elagabalus [above].

When Alexander was just 14, a rumour that he had been killed triggered his acclamation as Augustus.

Elagabalus and his mother were murdered by the Praetorian Guard, who threw the bodies into the Tiber and proclaimed Alexander as Augustus.

He ruled under the influence of his mother, Julia Avita Mamaea.

He was murdered by his army while confronting a Germanic invasion of Gaul.