I'm no coin collector, but after reading Gareth Harney's A history of Ancient Rome in Twelve Coins, I found this book listed in his suggested readings. The listed coins were chosen by a survey of various experts in the field. Many of the coins shown are very rare, with only a literal handful of them known. The coins have been ranked in order of their "greatness", but they appear in the book chronologically. They range from the first coin (an Ionian stater made of electrum, an alloy of gold and silver) to the last coin of the Roman Empire (made from melted silver taken from churches in Constantinople during its siege in 1453). The book is very well-designed with beautiful images of the obverse and reverse sides of the coins. It has an introduction on coin collecting, a glossary of the terms used, and an appendix showing all of the coins so that the reader can see their relative sizes.