1. A solar eclipse after the death of Julius Caesar.
Pliny states that there was a solar eclipse after the death of Julius Caesar. “Portentous and protracted eclipses of the sun occur, such as the one after the murder of Caesar the dictator…." Yet there were no solar eclipses visible from anywhere in the Roman Empire from Feb. of 48 B.C. through Dec. of 41 B.C., inclusive. On the other hand, in 49 B.C., there was a solar eclipse visible from Rome, on August 9, at 11:30 hours local time.

2. A comet after the death of Julius Caesar.
Pliny quotes Caesar Augustus as saying that he saw a comet soon after the death of Julius Caesar. “ ‘On the very days of my Games a comet was visible for seven days in the northern part of the sky. It was rising about an hour before sunset, and was a bright star visible from all lands.’ ”

The comet following the death of Julius Caesar was clearly seen from Rome in the northern part of the sky, and was rising about the time of sunset as seen from Rome. The comet of 44 B.C. does not fit this description, but the comet of 49 B.C. does. The comet of 49 B.C. was located in the northern part of the sky, was visible towards the end of the daylight hours, and could well have been rising at that time of day. Julius Caesar died in mid March of 49 B.C., not 44 B.C.

3. A solar eclipse before death of Augustus
Dio Cassius describes a solar eclipse as one of the portents occurring before the death of Caesar Augustus. He does not say how long before the death of Augustus, nor at what time of year, the eclipse occurred. The usual date given for the death of Augustus is August 19 of A.D. 14. However, an analysis of the solar eclipse data for the early first century A.D. shows that there were no solar eclipses visible from anywhere in the Roman Empire from A.D. 11 through A.D. 14, inclusive.

On the other hand, the solar eclipse on June 30 of A.D. 10 was a total solar eclipse, and was visible from most of Europe and most of Italy as a partial solar eclipse. If Augustus died on August 19 of A.D. 10, a solar eclipse occurring less than two months earlier, visible from most of the Roman Empire, would likely have been seen as a foreshadowing of his death. Caesar Augustus died in A.D. 10, not A.D. 14.

4. The length of the reign of Caesar Augustus
If Julius Caesar died 5 years earlier than the usual date, and Augustus died 4 years earlier than the usual date, doesn't that result in one year too many between those two events? No, in fact it solves a problem in the usual chronology of these events.

Flavius Josephus gives the length of Augustus’ reign as 57 years, 6 months, and 2 days in length (Ant. 18.32). Both Dio Cassius and Suetonius Tranquillus tell us that Augustus died on August 19. So, if his reign ended on August 19, it must have begun on February 17, six months and 2 days earlier. But Julius Caesar died on March 15. The problem in the usual chronology is that Augustus' reign is counted as beginning at a time when he had no real power in the empire.

The revised chronology (presented on this web site and in the book) unexpectedly solves this problem, because it gives an extra year between the deaths of Julius and Augustus. After the death of Julius Caesar, there was a power struggle. Augustus' reign could reasonably be counted as beginning the following year (11 months later), after he had consolidated power (along with Marcus Antony and Lepidus).

5. The Antedating of the Reign of Tiberius
Tiberius antedated his reign to a point about 10 years before the death of Augustus. This topic requires in-depth treatment. See this web page for an introduction to the topic and see the book for the full argument.

6. Claudius’ Comet and Eclipse
Both Suetonius and Dio describe a comet prior to the death of Claudius. According to Chinese astronomers, there was a comet fitting that description in both A.D. 39 (my revised date for the death of Claudius) and A.D. 54 (the usual date). See the book for details on these comets.

Dio describes an interesting situation during the reign of Claudius. The emperor Claudius knew from the calculations of Roman astronomers that a solar eclipse would coincide with his birthday. The Roman people considered eclipses to be omens of impending events, either of a change in leadership or of some misfortune. An eclipse coinciding with the birthday of an emperor is a very rare event and would have been interpreted by the Romans as very significant. They would likely have interpreted this event as indicating either an end to Claudius’ reign, or the beginning of some misfortune or disaster during his reign. In order to forestall any disturbance among the people as a result of this eclipse, Claudius issued a proclamation about the eclipse. His proclamation explained when the eclipse would occur and how long it would last, and gave a fairly scientific explanation as to why eclipses occur.

In the usual chronology, the solar eclipse on August 1 of A.D. 45 is considered to be this eclipse mentioned by Dio. That eclipse occurred in the morning and was centered in Africa, but would have been visible from much of Europe, including Rome, as a partial eclipse. Claudius’ birthday was August 1 and the usual chronology has his reign extending from Jan. of A.D. 41 to Oct. of A.D. 54.

In my revised chronology, Claudius reigned from Jan. A.D. 26 to Oct. A.D. 39, and the birthday eclipse occurred on August 1 of A.D. 26. That eclipse also occurred in the morning and was centered in Africa, but would not have been visible from Europe, nor from northern Africa. This eclipse was not visible from anywhere in the Roman Empire.

But why was Claudius concerned enough about a possible future solar eclipse to inquire of Roman scholars when the next one would occur? Dio states only that “some other portents had already occurred.” In the usual chronology, there were no other solar eclipses visible from the Roman Empire for more than a year previous to the August 1, A.D. 45 eclipse. But in the revised chronology, there was a solar eclipse visible from Rome on Feb. 6 of A.D. 26. This eclipse occurred only a couple of weeks after Claudius became emperor. This first eclipse of A.D. 26 was a partial solar eclipse that was visible from Rome at, and well after, dawn. This impressive eclipse would have been seen by the Roman people as an omen associated with the reign of Claudius, because it occurred so soon after he became emperor.

The first solar eclipse (Feb. 6 of A.D. 26) caused a stir among the Roman people, who were quite superstitious about eclipses. This caused Claudius to inquire when the next solar eclipse would occur. When Roman scholars informed Claudius of a second solar eclipse later that year, and one coinciding with his birthday, he became concerned about how the Roman people would interpret such an omen. For this reason, he issued his famous proclamation about the eclipse, in an attempt to prevent people from interpreting that eclipse as also an omen against him.

Now, if the eclipse mentioned in the proclamation had actually been visible from the Roman Empire, a proclamation by the emperor would not have been likely to cause the Roman people as a whole to abandon their belief that celestial events are meaningful omens. Yet Dio mentions no reaction by anyone to the eclipse of the proclamation. The August 1, A.D. 45 eclipse was visible from Rome and much of the Empire, but the August 1, A.D. 26 eclipse was not visible from the Roman Empire, but only from central and southern Africa. The reason there is no mention by Dio of any reaction to the eclipse is that it was not visible to the Roman people. The revised chronology can explain why Claudius sought information about a future solar eclipse (his reaction to the Feb. eclipse) and can explain the lack of any response from the Roman people after the August eclipse (it was not visible to them). The usual chronology offers no explanation of either of these points.

7. Nero's Comets
Tacitus mentions two comet sightings during the reign of Nero. Nero was so concerned about each of these two comet sightings (A.D. 60 and A.D. 64, usual dates), supposing it to be an omen of the end of his reign, that he massacred the Roman nobility in an attempt to divert this result. But the comet sighting of A.D. 64, according to Chinese astronomers, had no visible tail and may have been either a comet or a nova, and so it probably would not have been categorized as a comet by the ancient Romans and would not have elicited any response from Nero. Furthermore, in A.D. 65 and 66, two much more conspicuous comets were recorded by the ancient astronomers, but with no mention of any reaction by Nero by the ancient Roman historians. (The A.D. 66 comet was Halley's Comet.) The usual chronology does not fit the information on comet sightings.

As a result of the antedating of Tiberius' reign and the earlier dates for the deaths of Julius and Augustus, my revised chronology places the reign of Nero, 15 years earlier than the usual date. The revised dates for the reign of Nero gives us a much better fit for the comet information. See the book for details.

8. Vitellius: Comet and Eclipse Pair
Dio describes a lunar eclipse, occurring about the time of a comet sighting, during the summer when Vitellius was emperor. Vitellius was emperor for less than one year. The lunar eclipse occurred on either the 4th or the 7th of the month. A comet sighting paired with an eclipse falling on a particular day of the month is a very unusual event.

In A.D. 54, a comet was observed and recorded by the ancient Chinese astronomers. This comet had a tail measuring about 5 degrees and was seen between June 9 and July 9 of that year. In the following month, on August 7, a lunar eclipse occurred, which was visible from Rome before and during sunrise. There is no other year, in either the usual or my revised chronology, when a comet observation is followed by a lunar eclipse on either the 4th or 7th of the month.

The usual year for the summer of Vitellius’ reign is A.D. 69. There is no record of a comet observation by the ancient astronomers for the years A.D. 67 through 70, inclusive. Two lunar eclipses visible from Rome did occur in A.D. 69, one on April 25 and the other on Oct. 18. Neither of these eclipses fits Dio’s description, since neither occurred on the 4th or 7th of the month. Thus the pairing of a comet with a lunar eclipse (on the 4th or the 7th of the month) is rare enough so as to establish A.D. 54 as the only reasonable fit to Dio’s description.

9. Vespasian's Comet
Both Suetonius and Dio describe a comet that appeared before the death of Vespasian. The comet had a long, conspicuous tail and so was described as having long hair. The Roman people interpreted this as an omen that Vespasian would soon die. But Dio tells us: “To those who said anything to him about the comet he said: ‘This is an omen, not for me, but for the Parthian king; for he has long hair, whereas I am bald.’ ” Dio adds that the comet “was visible for a long time.”

The usual year given for the end of Vespasian’s reign is A.D. 79. There was a comet recorded by Korean astronomers in A.D. 79, which was described as a “broom star,” meaning that it had a conspicuous tail.961 However, that comet was only visible for about 20 days, and so does not fit Dio’s statement that Vespasian’s comet was visible for a long time. Also, there is no record of the comet of A.D. 79 from the observations of the Chinese astronomers.

There were two conspicuous comets in A.D. 65 to 66: a long-tailed comet seen from July to Sept. of A.D. 65, and Halley’s comet (also with a noticeable tail), seen from Jan. to April of A.D. 66. Both of these comets (A.D. 65 and A.D. 66) fit well the description of the comet preceding the death of Vespasian.

The comet preceding the death of Vespasian was visible for a long time. The two comets of A.D. 65 and A.D. 66 were seen from July to Sept. of A.D. 65 and Jan to April of A.D. 66. These two could easily have been mistaken as one comet, which seemed to be visible for an unusually long time. Thus the long-haired comet at the end of Vespasian’s reign was actually two comets, seen over much of the year preceding his death. Vespasian’s death must then be placed in June of A.D. 66, after an antedated reign of nearly 12 years (July of A.D. 54 to June of A.D. 66), not ten years as Dio stated. For an explanation and evidence on the length of Vespasian's reign, see chapter 13 of the book.

10. Vespasian's Solar and Lunar Eclipse Pair
Pliny states that an unusual celestial event occurred during the reign of Vespasian—a pairing of solar and lunar eclipses. “For the eclipse of both sun and moon within 15 days of each other has occurred even in our time, in the year of the third consulship of the elder Emperor Vespasian and the second consulship of the younger.” Vespasian, the emperor, had a son named Titus, whose surname was also Vespasian. So the year referred to here is the year in which the two consuls were the emperor Vespasian and his son, the younger Vespasian, who is usually called Titus.

In the usual chronology, Titus held his second consulship in the year A.D. 72, which coincided with Vespasian’s fourth consulship. Now, perhaps Pliny is counting Vespasian’s fourth consulship as his third, since, in the usual chronology, it was his third consulship after he became emperor. However, the pairing of a solar and lunar eclipse occurred in A.D. 71, not 72. There was a lunar eclipse on March 4, A.D. 71, visible from Rome, beginning just after sunset and lasting over 2 hours. A partial solar eclipse, visible from Rome, followed on March 20. Notice the incongruities here: these eclipses were 16 days apart, not 15 as Pliny states, and they occurred in a year in which Titus was not consul.

In my revised chronology, the fall of Jerusalem occurred in A.D. 56, the year of Vespasian’s third consulship. In A.D. 56, a lunar eclipse on June 16 was visible from Rome before and during dawn. A partial solar eclipse followed, 15 days later, on July 1. This solar eclipse was not visible from Rome, but was visible from other places within the Roman Empire, including:  all of Spain, most of northern Africa, southern France, and the island of Sicily.

More information can be found in the book and on the other pages of this web site. See the links below.