The book's title is taken from the Greek, and means "Iconoclast" or "breaker of the icon", and refers to Eikon Basilike, a Royalist propaganda work.
The piece was written with straightforward political aims, to stir up popular sentiment in support of the former monarch and to undermine the control of the Commonwealth government.
[3] Eikonoklastes, titled Eikonolastes in Answer to a Book Intitl'd Eikon Basilike, The Portrature of his Sacred Majesty in his Solitudes and Sufferings, was issued in two versions in October 1649, in English, and was enlarged in 1650.
[8] The central argument of Eikonoklastes involves the tyranny inherent in all monarchies, and Milton attacks the idea put forth by Charles I that the liberty of individuals consists[9] "in the enjoyment of the fruits of our industry, and the benefit of those Laws to which we our selves have consented".
[10] Milton's response is to point out how such a definition cannot actually separate different kinds of governments:[9] First, for in the injoyment of those fruits, which our industry and labours have made our own upon our own, what Privilege is that, above what the Turks, Jewes, and Mores enjoy under the Turkish Monarchy?
[16] In the second edition, Milton expanded his claim that the supporters of Charles I were[17] an "inconstant, irrational, and Image-doting rabble" to declare: that like a credulous and hapless herd, begott'n to servility, and inchanted with these popular institutes of Tyranny, subscrib'd with a new device of the Kings Picture at his praiers, hold out both thir eares with such delight and ravishment to be stigmatiz'd and board through in witness of thir own voluntary and beloved baseness.
[19] In addition to a discussion of Charles I and monarchy, Milton adds a response to Edward Hyde, 1st Earl of Clarendon, who wrote The History of the Rebellion and Civil Wars.
[20] Milton argues that in all monarchical governments there is potential for enslaving the population, which was an argument he previously relied on in his The Tenure of Kings and Magistrates.
The description of a rise of antichristian monarchs near the end of Eikonoklastes declares that such individuals rely on an ambiguous language to gain power.