It turns out Emperor Frederick II & my mother share the same birthday (different years). Gosh, that explains a lot.
The emperor grew up in Palermo, a Sicilian-Norman-Arabic blend of cultures.
He was attired for burial in a mixture of Cistercian & Arabic robes.
He was interested in mathematics : he sponsored & encouraged the famous Fibonacci.
He wrote a treatise on falconry which is still cited.
Castel del Monte is a weird, unusual place, sort of like my poem.
"Poets, envy the crystallographers!" (Mandelstam)
(I'm finding some of these facts in a book by Heinz Gotze, Castel del Monte.)