Explanation:
“The chief were those who, from the pit of Hell
Roaming to seek their prey on earth, durst fix
Their seats long after next the seat of God,
Their altars by his altar.” 
(Lines 381-384)

Answer: These lines have been taken from Milton’s ‘Paradise Lost’ Book-I, the great epic in English language. The poet here describes how the fallen angels were worshipped as idols of the Israelites in the ancient world.

Following the epic tradition, Milton has given a list of the fallen angels who responded to the call of Satan to wage a new war — open or secret — against their grand Foe, the Almighty. Milton invokes the Muse again in the lines immediately preceding those under reference. “Say, Muse, their names are then known, who first, who last/Roused from the slumber on that fiery couch,/At their great Emperor’s call.” All the names are not proposed to be mentioned by the poet. He wants to select the chief ones who had forfeited God’s grace and had been Heaven’s supreme kings. Some of these chiefs left the pit of hell in search of their prey on Earth. They became pagan gods and established their shrines near those of Jehovah.

The gods whose names are mentioned in the first group are the boldest and the wickedest. They are the false gods who succeeded in getting themselves worshipped by the Israelites in or in the immediate neighbourhood of the Temple in Jerusalem.

It may be mentioned here that for the first group of gods introduced by Milton in the lines that follow there is direct Biblical authority. Milton imagines their geographical proximity to Jehovah in his sanctuary to be evidence of their special boldness.