1.In the beginning of its history, Rome, as a republican state, was ruled by a Senate but governed by a monarch whose power was limited by the Senate. From BC 510-31 there were 10 such monarchs.
a. Cato the Elder,
b. Gracchi
c. Caius Marius
d. Lucius Cornelius Sulla
e. Pompey
f. Marcus Licinius Crassus
g. Cato the Younger
h. Julius Caesar – The Dictator period
i. Marc Antony
j. Lepidus
k. Augustus
2.The seven kings mentioned are those rulers who held Emperor status. No Roman ruler prior to BC 31 ever held Emperor status.
a. These five have fallen
Augustus, BC 31- AD 14 – the first to be granted the title of emperor
Tiberius, AD 14-37
Caligula, AD 37-41
Claudius, AD 41-54
Nero, AD 54-68
b. “One is,” refers to the king who was ruling at the time this revelation was given. In this verse, we have one of the clearest proofs for dating this book. When John saw this vision, Galba was Emperor. He would be one of the three who was rooted up. He only reigned for 7 months. This means that John saw this vision sometime between June of 68 and January of 69.
c. These three are rooted up
Galba, AD 68-69
Otho, AD 69 – The one who has not yet come who will reign for only 3 months.
Vitellius, AD 69 – reigned only 5 months from July 1 to December 20.
d.
“The other has not yet come and when he comes, he will remain only a
little while.”
This is quit descriptive of Otho who reigned for only 3 months from January 15 to April 16, AD 69 and Vitellius who reigned only 8 months from April 16 to December 22, AD 69. This would seem to suggest the time in which the beast “was and is not” and the wounding of the beast. These three briefly reigning emperors represent the three horns that were pulled out by the roots in Daniel's vision in Daniel 7. During the period of these three brief reigns, the beast was essentially dead. Rome had no official emperor during this time because the loyalty of the people had been divided between these three want-to-be dictators. These three were in competition for the title with each one claiming to be Caesar. This resulted in succession by murder.
e. Vespasian, AD 69-79 – The little horn – “who himself is an eighth.” The wound on the head is healed, (Revelation 13:3)
“He shall speak pompous words against the Most-High, shall persecute
the saints of the Most-High, and shall intend to change times and law.
Then the saints shall be given into his hand for a time and times and
half a time.” (25)
f. Titus, AD 79-81
g. Domitian, AD 81-96
Full of eyes
A pompous mouth
After Vitellius, Vespasian assumed the throne and reigned for 10 years from December of AD 69 to AD 79. It was under his reign that Rome began to stabilize politically. This is the “wound” that was healed, and the beast lived again. This is why in 13:3-4,
“the whole earth was amazed and followed after the beast; they
worshiped the dragon because he gave his authority to the beast; and
they worshiped the beast, saying, ‘Who is like the beast, and who is
able to wage war with him?’”
The reason John only mentions seven rather than ten is because the vision of John only concerns events up to the time of Vespasian. We find in Nero and Galba the terrible persecutors of the Christians at whose hand Peter and Paul were martyred. God used Nero to destroy the Jews. Nero commanded Vespasian to destroy Jerusalem. Nero was the fifth king, suggesting that Revelation was written before the siege of Jerusalem. Traditionally, Nero is the one who persecuted Christians beyond all comparison. John's banishment to Patmos was itself a result of the great persecution of Nero. The apostle Paul was presumably tortured and then beheaded by Nero at Rome in A.D 67. The apostle Peter, who traditionally crucified upside down, was another of Nero's victims.
3.
“The beast which was and is not, is himself also an eighth and is one
of the seven.”
a. Notice, it says the beast. Which beast – the one who “was and is not,” not one of the seven heads of the beast; thus, this is Rome itself.
b. “Is himself also an eighth.” An eighth what? He is the eighth king. The angel is identifying kings / emperors and he is “one of the seven.” This was Vespatian. His fate was to be the persecutor of God’s people.
4.
“The ten horns which you saw are ten kings who have not yet received a
kingdom, but they receive authority as kings with the beast for one
hour.” '
Horns' typically refer to power or authority. The ten horns represent the linage of emperors from August to Domitian. This does not take into account the brief reigns of Otho and Vitellius,
“They receive their authority from the beast for one hour.” In other
words, “for a little while.”
“These have one purpose, and they give their power and authority to
the beast. These will wage war against the Lamb...”
These kings exist only to give their power and authority to the beast – Rome. These join with the beast in the persecution of the saints – “war against the Lamb.”
As to your second question, yes; this is the fourth best in Daniel's vision in Dan 7.