Immediately after the prologue, Milton raises the question of how Adam and Eve’s disobedience occurred and explains that their actions were partly due to a serpent’s deception. This serpent is Satan, and the poem joins him and his followers in Hell, where they have just been cast after being defeated by God in Heaven.

Satan lies stunned beside his second-in-command, Beelzebub, in a lake of fire that gives off darkness instead of light. Breaking the awful silence, Satan bemoans their terrible position, but does not repent of his rebellion against God, suggesting that they might gather their forces for another attack. Beelzebub is doubtful; he now believes that God cannot be overpowered. Satan does not fully contradict this assessment, but suggests that they could at least pervert God’s good works to evil purposes. The two devils then rise up and, spreading their wings, fly over to the dry land next to the flaming lake. But they can undertake this action only because God has allowed them to loose their chains. All of the devils were formerly angels who chose to follow Satan in his rebellion, and God still intends to turn their evil deeds toward the good.

Once out of the lake, Satan becomes more optimistic about their situation. He calls the rest of the fallen angels, his legions, to join him on land. They immediately obey and, despite their wounds and suffering, fly up to gather on the plain. Milton lists some of the more notable of the angels whose names have been erased from the books of Heaven, noting that later, in the time of man, many of these devils come to be worshipped as gods.

Among these are Moloch, who is later known as a god requiring human sacrifices, and Belial, a lewd and lustful god. Still in war gear, these fallen angels have thousands of banners raised and their shields and spears in hand. Even in defeat, they are an awesome army to behold.

Satan’s unrepentant evil nature is unwavering. Even cast down in defeat, he does not consider changing his ways: he insists to his fellow devils that their delight will be in doing evil, not good. In particular, as he explains to Beelzebub, he wishes to pervert God’s will and find a way to make evil out of good. It is not easy for Satan to maintain this determination; the battle has just demonstrated God’s overwhelming power, and the devils could not even have lifted themselves off the lake of fire unless God had allowed it. God allows it precisely because he intends to turn their evil designs toward a greater good in the end. Satan’s envy of the Son’s chosen status led him to rebel and consequently to be condemned. His continued envy and search for freedom leads him to believe that he would rather be a king in Hell than a servant in Heaven. Satan’s pride has caused him to believe that his own free intellect is as great as God’s will. Satan remarks that the mind can make its own Hell out of Heaven, or in his case, its own Heaven out of Hell.

Satan addresses his comrades and acknowledges their shame in falling to the heavenly forces, but urges them to gather in order to consider whether another war is feasible. Instantly, the legions of devils dig into the bowels of the ground, unearthing gold and other minerals. With their inhuman powers they construct a great temple in a short time. It is called Pandemonium (which means “all the demons” in Latin), and the hundreds of thousands of demonic troops gather there to hold a summit. Being spirits, they can easily shrink from huge winged creatures to the smallest size. Compacting themselves, they enter Pandemonium, and the debate begins.

Throughout the first two or three books of Paradise Lost, Satan seems as if he’s the hero of the poem. This is partly because the focus of the poem is all on him, but it is also because the first books establish his struggle—he finds himself defeated and banished from Heaven, and sets about establishing a new course for himself and those he leads. Typically, the hero or protagonist of any narrative, epic poem or otherwise, is a person who struggles to accomplish something. Milton plays against our expectations by spending the first quarter of his epic telling us about the antagonist rather than the protagonist, so that when we meet Adam and Eve, we will have a more profound sense of what they are up against. But even when the focus of the poem shifts to Adam and Eve, Satan remains the most active force in the story.

One important way in which the narrator develops our picture of Satan—and gives us the impression that he is a hero—is through epic similes, lengthy and developed comparisons that tell us how big and powerful Satan is. For example, when Satan is lying on the burning lake, Milton compares him to the titans who waged war upon Jove in Greek mythology. Then, at greater length, he compares him to a Leviathan, or whale, that is so huge that sailors mistake it for an island and fix their anchor to it. In other epics, these sorts of similes are used to establish the great size or strength of characters, and on the surface these similes seem to do the same thing. At the same time, however, the effect of these similes is to unsettle us, making us aware that we really do not know how big Satan is at all. No one knows how big the titans were, because they were defeated before the age of man. The image of the Leviathan does not give us a well-defined sense of his size, because the whole point of the image is that the Leviathan’s size generates deception and confusion.

More than anything, the similes used to describe Satan make us aware of the fact that size is relative, and that we don’t know how big anything in Hell is—the burning lake, the hill, Pandemonium, etc. Milton drives this fact home at the end of Book I with a tautology: while most of the devils shrink in size to enter Pandemonium, the important ones sit “far within / And in their own dimensions like themselves” (I.792–793). In other words, they were however big they were, but we have no way of knowing how big that was. Finally, it is important to note that the first description of Satan’s size is the biggest we will ever see him. From that point on, Satan assumes many shapes and is compared to numerous creatures, but his size and stature steadily diminishes. The uncertainty created by these similes creates a sense of irony—perhaps Satan isn’t so great after all.

The devils in Paradise Lost are introduced to the story here in Book I in almost a parody of how Homer introduces great warriors in the Iliad. The irony of these descriptions lies in the fact that while these devils seem heroic and noteworthy in certain ways, they just lost the war in Heaven. As frightening and vividly presented as these creatures are, they did not succeed in killing a single angel.

In Book I, Milton presents Satan primarily as a military hero, and the council of devils as a council of war. In doing so, he makes Paradise Lost resonate with earlier epics, which all center around military heroes and their exploits. At the same time, Milton presents an implicit critique of a literary culture that glorifies war and warriors. Satan displays all of the virtues of a great warrior such as Achilles or Odysseus. He is courageous, undaunted, refusing to yield in the face of impossible odds, and able to stir his followers to follow him in brave and violent exploits. Milton is clearly aware of what he’s doing in making Satan somewhat appealing in the early chapters. By drawing us into sympathizing with and admiring Satan, Milton forces us to question why we admire martial prowess and pride in literary characters. Ultimately he attempts to show that the Christian virtues of obedience, humility, and forbearance are more important.