Byzantine coins have a wide variety of mintmarks. Here is one that is fun: This is a large (33-32 mm) year 13 (XIII = 539/540) 20-nummia piece of Justinian (527-565). "K is the numeral for "20" in Greek, so the large K states the denomination. The mint is Cyzicus, which is also spelled Kyzicos, and its mintmark on the 40-nummia piece is KYZ. But here, with a large K already there, they decided to complete the mintmark with "YZ" smaller below. That's a cute way to give the mintmark! Sear 208, year 13. 33-32 mm. 9.58 grams. Show us an interesting mintmark!
Two birds with one stone! That engraver had better have gotten a bonus solidus for his ingenuity. Siscia mint-marks are always interesting to me. No idea why they include interesting symbols, like a sunrise, in the mark.
Here's a nearly similar one to C.A.'s coin also from Siscia. But not Constantine, rather his son Crispus. If Art is Fun, then Fun is Art too.
My favorite is the Constantine eros mark from Rome. They come in two reverses and for five rulers. R EPW C officina (here gamma) The monogram EPW and C (sometimes the C is attached) is Greek eros (love) which translates into Latin AMOR which, spelled backwards is ROMA. Constantine I with Roma AETERNAE reverse Licinius I /VOT XX Crispus Constantine II / VOT V I lack the Licinius II and need to update most get legible oficinae.
I love those instances of ancient personality that sometimes come out in coins. Great coin! Heres' a fun mint mark on a new-ish coin... an Aurelian with a Lion mint mark.
I also like the Constantine-era two captives mint marks from Lugdunum: Lugdunum (Lyons) mint, A.D. 320 RIC 79 (var.)* Obv: CON-STANTINVS AVG Rev: VICTORIAE LAET PRINC PERP - Two Victories holding shield inscribed VOT/PR above altar P[2 captives]L in exergue 19 mm, 3.2 g. *obverse inscription break