As astonishing as it may seem, the great Puritan poet, John Milton, seems to have become a Catholic several years before his death, and to have remained a papist until his death. Evidence that Milton is amongst the illustrious list of literary converts is given in a footnote on p. 71 of my book, Through Shakespeare’s Eyes. 

Here is the full text of the footnote :

Intriguingly, and astonishingly, a letter to the Tablet, published May 23, 1908, less than a year after Chesterton wrote these words, provides documentary evidence of the unthinkable fact that Milton may also have died a Catholic. As unbelievable as this may seem, the evidence is provided by the respected historian W. H. Gratton Flood from a reputable source. While searching in the seventh report of the Historical Manuscripts Commission, Gratton Flood came across the following statement from the autobiography of Sir John Percival, in volume 2 of the Egmont Papers: “Milton, the poet, died a Papist. Dr Charlotte, Master of University College, Oxford, told me lately at Bath that he remembers to have heard from Dr Binks that he was at an entertainment in King James’ reign, when Sir Christopher Milton, one of the Judges, and elder brother to the famous Mr Milton, the poet, was present; that the Judge did then say publicly his brother was a Papist some years before he died, and that he died so. I am still more persuaded of it from what Dr English told me that he often heard Mr Prior, the poet, say that the late Earl of Dorset told him the same thing.”