John Milton was an English poet, polemicist, man of letters, and a civil servant for the Commonwealth of England under Oliver Cromwell. He wrote at a time of religious flux and political upheaval, and is best known for his epic poem Paradise Lost, written in blank verse. Milton's poetry and prose reflect deep personal convictions, a passion for freedom and self-determination, and the urgent issues and political turbulence of his day. Writing in English, Latin, Greek, and Italian, he achieved international renown within his lifetime, and his celebrated Areopagitica —written in condemnation of pre-publication censorship—is among history's most influential and impassioned defenses of free speech and freedom of the press. William Hayley's 1796 biography called him the "greatest English author," and he remains generally regarded "as one of the preeminent writers in the English language," though critical reception has oscillated in the centuries since his death. Samuel Johnson praised Paradise Lost as "a poem which...with respect to design may claim the first place, and with respect to performance, the second, among the productions of the human mind," though he described Milton's politics as those of an "acrimonious and surly republican".