Knowledge is like money: to be of value it must circulate, and in circulating it can increase in quantity and, hopefully, in value. Louis L'Amour . ( I wrote this for forum Ancient Coins, I thought I would share it here as well. This is part one, it has already been completed but photos need to be sorted. I realize only aa small group on the board will find this of interest.) When you specialize in a denomination you learn more than the average collector and in other cases more than the numismatists who looked at the currency as a whole instead of specializing in one solitary denomination. Here is what I learned on the way. To start Michael Hendy in Coinage and Money 12-13th century published in 1969 was the genesis for accurate information regarding the 12th century coinage especially the tetarteron , his work changed previous collectors catalogs that had categorized the tetarteron without a name , simple described as small flat coins. In the reign of Alexius, the coinage of the Eastern Roman empire (Now known as Byzantine) was in horrible condition, a coinage that was once respected around the world was debased and its value was becoming in question. The empire was cash poor but in 1092 Alexius did the first major change in the coinage of the empire since Justinian. In this coin reform of 1092, he created several new denominations, a scyphate gold coin called a Hyperpyron. The coin was originally 20 1/2 carats gold, it returned Byzantine currency to the forefront or respect of its neighboring nations and a basic unit of standards for other cultures to follow for the next few century. Bellow the Hyperpyron was the Aspron trachy also known as trikephalon, the coin was a mixed metal coin originally containing 6 carats of gold. Trikephlon is the appropriate name based on contemporary writings, In the collecting world it is known as the Aspron trachy. ( To avoid confusion I have noticed several dealers using Aspron trachy for the billion trachy , beware of this.) Then come the billion trachy, a scyphate coin that is seen in many collections, it contained as much 8% silver in the time of Alexius reign but oddly the 12th century coinage was not found in Greece it was found in Constantinople and the eastern empire of Asia minor. For some unknown reason the Byzantine government kept the trachy separate from the tetarteron except in Constantinople and the immediate outlying regions. Now dealing with the focus of this post, the tetarteron. It originally received its name from a gold coinage that was minted before the reform but in the same shape. In the original writings of Michael Hendy he broke them into two groups the tetarteron and its half, but he came up with this separation by using the average weights for the coins, the full version and the half. However, in his original book he left the door open to the coin being multiple denominations. ( CAM pg 29) Hendy does add to the family of tetartera by the time he is asked to write Dumbarton Oakes Catalog IV, but not because of weight or size , he adds the Constantinople issues as a sperate denomination. A study conducted by D.M. Metcalf proved the issues from Constantinople contained silver, around 4%, not much, but when you consider the trachy was only 8% silver content then in comparison it was considerable. DOC IV retests the results and they were proved to be conclusive. However, no catalog written after DOC IV noted the difference in denominations, Sear had already written his catalog based on the 1969 work. Therefore, most of the collecting community is oblivious to this fact. Michael Hendy believed this Constantinople minted coin was terrified at a higher rate than the Thessalonica minted because of the silver content, it was not until correspondence written between a student a teacher was this given additional evidence to be true. In the two letters the purchasing power of the two coins were described, a standard Thessalonica minted tetarteron could purchase a small loaf of bread where a Constantinople issue could buy 10 mackerel. ( Pagona , Small change) The Constantinople issues are rare, in fact Phillip Grierson did not think they were regular issues, but coins issued for ceremonial reason s alone. Michael Hendy disagreed and after my years of collecting I must disagree as well. Although they are rare, they are found as circulated coins. During the time of their original issue I believe the Constantinople issues were differentiated by a silver wash, the same silver wash that was put on trachea of the same time period. I have seen numerous examples with slight traces of silver still intact and several examples of tetartera that the silver was still intact, my main collection has one example, basically a coin as struck. Ironically, the coin would be far more attractive without the silvering. Now trachea and tetartera (Both Constantinople issues and Thessalonica issues) had one thing in common they were created never to be recalled. In other words, the coins were to remain in circulation as long as possible. Taxes were to be paid in gold and only gold, change from taxes was paid in the trachea or tetartera. The government never made any attempt to recall tetartera, this accounts for the condition most tetartera is found in, a coin that circulated for decades after its creation. This also creates the need for imitation coins minted after the ruler’s death. I will discuss this further later in the post. Now the main references for the collectors of 12th century tetartera are Coinage and Money in the Byzantine Empire 1081-1261– Michael Hendy – This is the genesis for collecting coinage from this time period, it is the original road map for the organization of the coinage but it is a rarer publication and no longer necessary for the average collector. Sear Byzantine Coins and their Values- This publication is the easiest way for Byzantine collectors to communicate. The majority of the tetartera are included in this book, however, it was written before the Dumbarton Oakes catalog leaving many Byzantine collectors in the dark about the new information of Metcalf and Hendy’s findings on Constantinople issue containing silver. Most dealers use this as the main reference. Dumbarton Oakes Catalog Volume IV- This is the most scientific of all catalogs for tetartera collectors, Michael Hendy does cite information in his 1969 publication but the new information he includes on issues supersedes his earlier work. The catalog was expensive at its release, but it is now available for free online. https://www.doaks.org/research/publ...collection-and-in-the-whittemore-collection-4 Two other coin catalogs appear after the publication of DOC IV but sadly in both cases they ignore the new information and follow in the footsteps of Sear. De Munzen Des Byzantinischen Reiches 491- 1453 by Andreas Urs Sommer -Interesting catalog but written in German and not all issues are included, however the prices in Euro are far more accurate than Sears catalog written decades before. Catalog of the Late Byzantine Coins 1081-1453 Volume I- This catalog in invaluable for its line drawings but most of the authors findings are opinions not backed by fact, and once again they completely ignored the findings of DOC IV , the catalog did add a very interesting theory regarding die sizes to determine the full and the half . I explored the theory and found it was not complete, however my final findings are not conclusive but does leave the door open for further exploration. My other criticism of the work is they never cited their sources for coins, sizes and weights, I think they used coin archives but that was not made clear, the catalog is the first to publish several new types of tetarteron. One thing several catalogs attempt to do is determine rarity , this is done by either by monetary value or by a numerical system, I have found this to be very inefficient and nonfactual, many coins in Sear cited as being common took me years to find. I have found the best system to determine rarity are the archaeological finds at Corinth, Athens and now recently Thessalonica. Knowing how many of a type appears in their records seems to give the best rarity system. This is cumbersome, a more practical method is coin archives. DOC IV noted the first issues of tetartera were created in lead, this was done because the government of Alexius I Comnenus had a huge shortage of copper, we know this because it is noted in history books that he had church fixtures and city statues melted down to be used for coinage. The use of lead in Byzantine coinage was not new, it had first been done during a metal shortage by Maurice Tiberius who ruled 582-602. The Alexius lead issues are three different types, none of them are listed in Sear but they are in DOC and CLBC, The rarest of the three was offered by Forum Ancient Coins when they brought a small group to market, beyond that I have never seen them offered elsewhere. One example of a fourth type was offered at auction but without further examination or other examples of this unlisted coin it is difficult to add it as a new type. Here is a nice example of a known lead coin of Alexius minted in Constantinople. The Constantinople issues of the tetartera with silver are skillfully created the imagery remained detailed and uniform. The silver content is rarely visible by the eye sometimes traces of the silver wash Alexius Issued 4 Constantinople issues. SBCV-1920 ,SBCV-1921,SBCV-1922,SBCV-1923 All are difficult to find however SBCV-1921 and SBCV-1922 are particularly elusive. Alexius Issued 7 tetartera from the Thessalonica mints. Thessalonica issues tend to also be uniform but looser in style. The early issues of Alexius I were in many times done in haste, to find any in excellent condition, nicely centered , well struck, light wear is the rarity with these coins. They also can be commonly found overstruck on earlier follis from the Anonymous follis series, especially class K. SBCV-1929, SBCV-1930 (Harder to find but very rare in a clean strike, normally very messy strike.) SBCV-1931, SBCV-1932 (A half tetarteron that is extremely difficult to find nicely struck, it also a coin that is commonly found imitated, more about imitations later in the post. Also Michael Hendy listed this as being struck at an unknown mint, recently at a new excavation for the new Thessalonica subway system it was found in such great quantities that it supports the new theory it was actually minted in Thessalonica.) SBCV-1933 (Interesting coin, in Sear and DOC it is a full tetarteron in Sommer it is listed as a half. I have examples from 1gm to 5.6gm, again weights will be discussed further down in the post.) One of my favorites. Last, DOC 41, not listed in Sear , 3 examples are known in the world today. It has a monogram of Alexius. ( Pictured later in post.) To Be Continued.