John William Cousin, A Short Biographical Dictionary of English Literature… (1910)
“ Sidney, or Sydney, Algernon (1622-1683) . -- Political writer, s. of the 2nd Earl of Leicester, and grand-nephew of Sir Philip S., in his youth travelled on the Continent, served against the Irish Rebels, and on the outbreak of the Civil War, on the side of the Parliament. He was one of the judges on the trial of Charles I., and though he did not attend, he thoroughly approved of the sentence. He opposed the assumption of the supreme power by Cromwell. After the Restoration he lived on the Continent, but receiving a pardon, returned in 1677 to England. ”
