Caligula

Caligula (AD12-41) succeeded his father Tiberius as Roman Emperor in AD37. Popular at first, thanks to his liberality and the illustrious reputation of his father, a serious illness seemed to affect his sanity and he declared himself a god. Caligula built a temple to himself as Jupiter Latiaris then hearing of the imageless worship in the Jerusalem Temple, he decided to set up his own life-sized statue in the Holy Place. His advisers beseeched him not to do so, fearing a bloody civil war, but Caligula won’t budge. However, he was assassinated before he could carry out his plan of desecration.

Julius Caesar

The Roman general and dictator Julius Gaius Caesar (102-44BC) is considered to be Rome's most successful military commander. As governor of Cisalpine Gaul, he conquered Gallic territory up to the river Rhine, suffering only two reverses in this period and his brilliance as a general led to his great victories at Pharsalus in 48 BC, Thapsus in 46 BC, and in 47 BC against King Pharnaces II in Asia Minor, a campaign he famously summarized as veni, vidi, vici (‘I came, I saw, I conquered’).
The leader of a highly efficient and fanatically loyal army, Caesar earned his troop's respect by leading by example and showing a humility many of today's Christian leaders can learn from. When his army were digging in he seized a spade and gave a hand. He ate the same food and drunk the same wine as his men and refused to sleep in a tent when his men were out in the cold and wet.

Augustus

Augustus was the title of Octavian (born Gaius Octavius), the first Roman emperor 31 BC–AD 14. He reformed the government of the empire, the army, and Rome's public services, and was a patron of the arts. The period of his rule is known as the Augustan Age.
Augustus strongly supported the worship of Roman gods, especially Apollo, and depicted Roman defeat of Egypt as Roman gods defeating Egypt's. He sponsored Vergil's Aeneid in the hope that it would increase pride in Roman heritage. The emperor forbade his own deification as he didn't want to upset the upper class Romans, but willingly received all the marks of piety bestowed upon him.
Augustus is mentioned in the Bible in a clear example of a non-believer fulfilling God's will by issuing a decree that a census be taken of (Luke 2 v1) the entire Roman world. As a result Joseph and his family had to register at his home town of Bethlehem. Thus the prophecy about the Messiah being born in Bethlehem in the Old Testament book of Micah (Chapter 5 v 2) was fulfilled.
Augustus was not unfriendly towards the Jews and respected their worship and institutions.