This passage from the end of Gibbon's chapter 29 and the accompanying footnote sparked off a memory.
His subjects, who attentively studied the character of their young sovereign, discovered that Honorius was without passions, and consequently without talents; and that his feeble and languid disposition was alike incapable of discharging the duties of his rank, or of enjoying the pleasures of his age. In his early youth he made some progress in the exercises of riding and drawing the bow; but he soon relinquished these fatiguing occupations, and the amusement of feeding poultry became the serious and daily care of the monarch of the West, (61) who resigned the reins of empire to the firm and skilful hand of his guardian Stilicho.
Note 061 Procopius de Bell. Vandal. 1. i. c. 2 [tom. i p. 316, ed. Bonn.]. I have borrowed the general practice of Honorius, without adopting the singular, and, indeed, improbable tale, which is related by the Greek historian.
I knew there was a painting called "Honorius and His Favourites". If asked, I would have said with every confidence that it was by Alma-Tadema, but I would have been wrong. Fortunately, when I googled Honorius Alma-Tadema, Adrian Murdoch's Bread and Circuses blog popped up with a post pointing me to John William Waterhouse as the artist. This copy of the picture comes from a site devoted to John William Waterhouse's life and works. Bread and Circuses also has a translation of the anecdote in Procopius, though it's not clear whether it's Adrian Murdoch's own translation or one he found elsewhere.
The above image is courtesy WATERHOUSE, the art and life of John William Waterhouse. You can zoom in for details.