Letters of reconciliation were dispatched to Rome extending amnesty to the Senate and recognizing the laws, while also condemning the administration of Macrinus and his son.

M. Opelius Diadumenianus was the son of Macrinus, born in 208.

* Diadumenianus, son of Macrinus, escapes to the Parthian court, but is captured at Zeugma and also put to death.

** Diadumenian, son of Macrinus

According to sources, the downfall of Plautianus was largely due to suspicion of Severus ' son Caracalla, who was himself later murdered and replaced by his Praetorian prefect Marcus Opellius Macrinus.

On June 8, 218 near Antioch, Gannys, Elagabalus ' tutor, defeated Macrinus and his son, with the help of the III Gallica and the other legions of the East.

Once back in Syria and possessed of ample funds, Maesa engaged in a plot to overthrow Macrinus and place one of her grandsons, Elagabalus son of Julia Soaemias, in his place.

Together with her mother, Julia plotted to replace Macrinus with her son Varius Avitus Bassianus.

Diadumenian () ( 14 / 19 September 208 – 218 ), was the son of the Roman Emperor Macrinus, and served his father briefly as Caesar ( May 217 – 218 ) and as Augustus ( in 218 ).

* 218, Execution of Emperor Macrinus and his son by Praetorian Guard.

* 217 – Roman Emperor Caracalla is assassinated ( and succeeded ) by his Praetorian Guard prefect, Marcus Opellius Macrinus.

In 217, the emperor Caracalla was assassinated and replaced by his Praetorian prefect, Marcus Opellius Macrinus.

When the emperor Macrinus came to power, he suppressed the threat against his reign by the family of his assassinated predecessor, Caracalla, by exiling them — Julia Maesa, her two daughters, and her eldest grandson Elagabalus — to their estate at Emesa in Syria.

Caracalla and Julia Domna were both deified by the Senate, both Julia Maesa and Julia Soaemias were elevated to the rank of Augustae, and the memory of both Macrinus and Diadumenianus was condemned by the Senate.

* 218 – Julia Maesa, aunt of the assassinated Caracalla, is banished to her home in Syria by the self-proclaimed emperor Macrinus and declares her 14-year old grandson Elagabalus, emperor of Rome.

After months of mild rebellion by the bulk of the army in Syria, Macrinus took his loyal troops to meet the army of Elagabalus near Antioch.

This revolt spread to the entire Syrian army ( which, at the time, was swollen with troops raised by the Emperor Caracalla, and not fully loyal to Macrinus ), and eventually they were to win the short struggle that followed by defeating Macrinus at a battle just outside Antioch.

* Summer – Battle of Nisibis: The Roman army under command of Macrinus, is defeated in a three days battle by the Parthians at Nisibis ( southern Turkey ).

* May 16 – Julia Maesa, an aunt of the assassinated Caracalla, is banished to her home in Syria by the self-proclaimed emperor Macrinus and declares her grandson Elagabalus, age 14, emperor of Rome.

Caracalla was succeeded by his Praetorian Guard Prefect, Macrinus, who ( according to Herodian ) was most probably responsible for having the emperor assassinated.

Mauretania gave to the empire one emperor, the equestrian Macrinus, who seized power after the assassination of Caracalla in 217 but was himself defeated and executed by Elagabalus the next year.

* Marcius Agrippa, a slave of the 3rd century who was eventually elevated to senatorial rank by Macrinus

This initially unexpected and humiliating defeat for Rome was followed by numerous campaigns over the next two centuries entailing many notable engagements such as: the Battle of Cilician Gates, Mount Gindarus, Mark Antony's Parthian Campaign and finally culminating in the bloody Battle of Nisibis in 217 AD, which resulted in a slight Parthian victory and Emperor Macrinus being forced to concede peace with Parthia.

During this trip, Caracalla was assassinated and succeeded ( briefly ) by Macrinus.

He argued that as far as is known Marius did not write a biography of Lucius Verus, even though the biography of that prince in the History is mainly of good quality, and that ' Ignotus ' only went up to Caracalla, as is revealed by the lamentable biography of Macrinus.

In the following year, however, the II Parthica, stationed in Apamea ( Syria ), abandoned Macrinus and sided with Elagabalus ; the Second supported Elagabalus ' rise to purple, defeating Macrinus in the Battle of Antioch.

In 218, during Macrinus reign, Julia Maesa went to Raphana, Syria, where the legion was based under the command of P. Valerius Comazon Eutychianus.

Following the death of Caracalla, Julia Maesa rescued the Severan Dynasty from the usurper Macrinus.

Caracalla's mother, Julia Domna, and his aunt, Julia Maesa, were suspicious of Macrinus ' role in the death of Caracalla, and returned home to Syria.

The Persians were driven back but then Macrianus proclaimed his two sons Quietus and Macrianus ( sometimes wrongly spelled Macrinus ) as emperors towards the end of the summer of that year.

The two Julias were successful, mainly because Macrinus was of an obscure origin without the proper political connections, and Elagabalus became emperor.

With one decision, Macrinus alienated most of the Roman establishment and made his own political destruction inevitable — so much were the frumentarii resented.

The Battle of Antioch ( June 8, 218 ) took place between two Roman armies of the Roman Emperor Macrinus and his contender Elagabalus, whose troops were commanded by general Gannys.

Macrinus was defeated on 8 June 218, at the Battle of Antioch.

When Macrinus was defeated on 8 June 218, at Antioch, Diadumenian's death followed his father's.

* In the Battle of Antioch ( 218 ), Elagabalus defeated Macrinus and become Roman emperor.

Caracalla's successor, the Praetorian Prefect of the Guard Macrinus, was defeated at Nisibis and concluded a peace with Artabanus, in which he gave up all the Roman conquests, restored the booty, and paid a heavy contribution to the Parthians.

General Gannys, the Commander of Elagabalus's forces, marched against him and Macrinus was decisively defeated just outside Antioch on 8 June 218, with most of his forces abandoning him.

* 218 – Macrinus deposed and executed, Elagabalus is installed on the throne

The biography of Macrinus is notoriously unreliable, and after a partial reversion to reliability in the Elagabalus, the life of Alexander Severus, one of the longest biographies in the entire work, develops into a kind of exemplary and rhetorical fable on the theme of the wise philosopher king.

The fictional character of general Maximus Decimus Meridius ( played by Russell Crowe in the movie Gladiator ) was partially based on Narcissus alongside being based on Marcus Aurelius's general Marcus Nonius Macrinus, Spartacus, Cincinnatus and Maximus of Hispania.

Macrinus was recognised by a centurion at Chalcedon on the Bospurus, taken back to Antioch and killed.

* Roman Empire Net article on Macrinus