Short answers, pulled from the story.
Lucius Verus was Roman emperor from 161 until his death in January or February 169. He ruled jointly with his adoptive brother Marcus Aurelius, marking the first time the Roman Empire was governed by two co-emperors simultaneously.
When Antoninus Pius died on the 7th of March 161, the senate intended to confirm Marcus Aurelius alone, but Marcus refused to take office unless Lucius received equal powers. Despite their nominal equality, Marcus held more authority, having been consul one more time than Lucius and serving as the sole Pontifex maximus.
The war began when Vologases IV of Parthia invaded Armenia in 161. Roman forces eventually captured Artaxata in 163, installed a new king in Armenia, retook Edessa and Nisibis, and reached Seleucia and Ctesiphon in 165, burning the Parthian royal palace. Lucius took the titles Armeniacus, Parthicus Maximus, and Medicus, though most of the military success was credited to subordinate generals including Statius Priscus and Avidius Cassius.
Lucius Verus took a mistress named Panthea from Smyrna while based in Antioch. She was musically inclined, spoke Ionic Greek, and exercised enough influence over Lucius that she persuaded him to shave his beard, for which the Syrians mocked him.
Lucius Verus died in January or February 169, shortly after falling severely ill while returning from the Danubian frontier with Marcus Aurelius. Some ancient sources suggested poisoning, but the more probable cause is the Antonine Plague, a widespread epidemic that had spread through Roman armies returning from the Parthian campaign.
After Lucius Verus died, Marcus Aurelius accompanied his body to Rome and offered games in his memory. The Roman Senate then voted Lucius divine honors, and he was worshipped as Divus Verus, the Divine Verus.