[Chesterton] wrote [St. Francis of Assissi] in 1924. It was reviewed in Italy by a young priest named Giovanni Battisti Montini. He saw something prophetic in Chesterton’s words. Forty years later, this priest would be Pope Paul VII am not able to read Italian, but for those who do, I believe this is the review.
Incidentally, GKC mentions in his book The Resurrection of Rome that when he met Pope Pius XI in Rome in 1929 (who on GKC's death named him a "Defender of the Faith") that the Pope said "some very generous things about a sketch I wrote of St. Francis of Assisi."