The identification of local gods with similar Greek deities, a practice termed 'Interpretatio graeca', facilitated the building of Greek-style temples, and the Greek culture in the cities also meant that buildings such as gymnasia and theaters became common. Many cities maintained nominal autonomy while under the rule of the local king or satrap, and often had Greek-style institutions. Greek dedications, statues, architecture and inscriptions have all been found. However, local cultures were not replaced, and mostly went on as before, but now with a new Greco-Macedonian or otherwise Hellenized elite. An example that shows the spread of Greek theater is Plutarch's story of the death of Crassus, in which his head was taken to the Parthian court and used as a prop in a performance of The Bacchae. Theaters have also been found: for example, in Ai-Khanoum on the edge of Bactria, the theater has 35 rows – larger than the theater in Babylon.

The practice of identifying local gods with Greek deities is called what?