The project Nomisma.org was initiated by the American Numisamtic Society in 2010. The original aim was to facilitate the online presentation of numismatic concepts employing the methods of the Semantic Web and Linked Open Data. In this way Nomisma.org laid the foundation for the machine-based exchange of data between systems. The online provision of descriptions of individual coin types, in particular of the coinage of the Roman Republic (Roman Republican Coinage – RRC) and the Roman Empire (Roman Imperial Coinage – RIC), has now been transferred from Nomisma.org to the online resources Coinage of the Roman Republic Online (CRRO: http://numismatics.org/crro/) and Online Coins of the Roman Empire (OCRE: http://numismatics.org/ocre/).

Nomisma.org and OCRE/CRRO can now be used by both coin cabinets and inventories of archaeoological coin finds in order to exchange data, as well as to publish them online. In the project Antike Fundmünzen in Europa (AFE: http://afe.fundmuenzen.eu/) at the Römisch-Germanische Kommission, we make use of the resources of Nomisma.org in order to provide common access via a Metaportal to various international online coin find data repositories. The use of LOD also means that by publishing our information on coin finds, these coins in turn serve as instances of the corresponding coin types in CRRO and OCRE, alongside the coins from museums and collections presented there, adding a geographical element to the resources.

In this presentation the emphasis will be placed on a practical demonstration of how the data are linked in order to show just what is possible at present. But it will also explain also how this is achieved and present the underlying ontology. Nomisma.org, AFE and OCRE/CRRO are already linked to various other thesauri, gazetteers and systems such as Getty, Pleiades, Geonames or Zenon, and we are at present concentrating on the incorporation of such widely-used resources in order to link numismatic data with other archaeological information.

The experience of Nomisma.org provides useful lessons that can applied productively to other archaeological material.