The narration that Henry is reading is a shortened (but marvelous) version of Bede's parable of the sparrow, written in 731 "The Ecclesiastical History of the English People". ""When we compare the present life of man on earth with that time of which we have no knowledge, it seems to me like the swift flight of a single sparrow through a banqueting hall on a winter's day. After a few moments of comfort, he vanishes from sight into the wintery world from which he came. Even so, man appears on earth for a little while, but of what went before his life, or what will follow, we know nothing."
Oh nice, he was quoting something? I have noticed they did do their research here and there even though it is very fictionalised. And I assume the poem/song that Duke Suffolk reads of Duke Surrey is real too? "The quiet mind."