@BenSi Here is some information, which I gathered, and which I posted previously, in a different thread. I'm not an expert on this subject. Comments, corrections, and additional information are welcome. The short answer : I think that, your smaller Anastasius folles, were minted before your large Anastasius follis was minted. The long answer, regarding the size of Byzantine 40 nummi folles, in general : The average "nummus" bronze coin declined from 10 grams in weight and 30 mm in diameter with 5% silver during the time of the Tetrarchy including Diocletian in 294 AD, to approximately 1 gram in weight and 10 mm in diameter with no silver by the time of Anastasius I in 498 AD. Then, in 498 AD, Anastasius I created a 40 nummi bronze coin, called a "follis" by present day numismatists, which was supposed to be worth 40 of the old small nummus coins (therefore it had the Greek numeral for 40, the letter "M", on the reverse). However, the first version of the 40 nummi coin weighed only 3 grams to 10 grams, and had a diameter of 20 mm to 25 mm. Ordinary citizens were unhappy with it, because its weight was nowhere close to the weight of 40 of the old small nummus coins. Therefore, in 512 AD, Anastasius I created a larger version of the 40 nummi coin, which weighed between 15 grams and 20 grams, and had a diameter of 31 mm to 40 mm. This coin still did not weigh as much as 40 of the old small nummus coins, but it was large enough and impressive enough that ordinary citizens accepted it. The 40 nummi coin represented further inflation, because it weighed way less than 40 of the old small nummus coins. But at least the average bronze coin was large again, and therefore more useful as coinage, along with new 20 nummi coins, 10 nummi coins, and 5 nummi coins. After reaching a maximum diameter of up to 45 mm in 540 AD under Justinian I, the 40 nummi coin gradually shrank to 14 mm to 18 mm in diameter by the end of the 8th century AD, and lost the letter "M" on the reverse, as the Byzantine Empire lost northern Africa including Egypt, most of Italy, and the Holy Land. The 40 nummi follis coin grew larger again in the 9th century AD (Why? I don't know), growing to a diameter of 25 mm to 30 mm. In 1092, the 40 nummi follis coin was replaced by small tetarteron bronze coins (16 mm to 21 mm diameter) and larger, thin, cup shaped trachy bronze coins (initially 30 mm or so, initially with 6% or 7% silver, but eventually having almost no silver, and then shrinking during the 14th century AD). Toward the bitter end of the Byzantine Empire, in the 14th century AD and 15th century AD, there were other, mostly small, bronze coins, called "assarion" (small), "follaro" (small), "stamenon" (sometimes larger), and "tornese" (small).