Hittites

The Hittites were an ancient empire, in power between the 16th and 12th centuries BC, situated in what later became Anatolia. Their empire ranged from the Tigris and Euphrates rivers in the East, to Damascus in the South, North to the Black Sea and East to the confines with Greece. In fact the city of Troy was under their vassalage (or, to be precise, was a confederate state).

The principal God of the Hittites was the God of storms. Different dialects gave him slightly different names, but the Luwians (whose dialect was the most spoken in the Hittite empire) called him Tarhunt, and he was represented by the Bull. In fact, the Luwians, as opposed to the people from Hattusa, where the Hittite capital was, had a Genitive form in their language, which can be found in place names ending with -assa. So the southern shore of what is now Turkey, which was called Tarhuntassa, meant land of the Storm God. This phenomenon lasted into Ancient Greece, which place names ending in -assos having the same Genitive meaning.

If the God of storms seems like an arbitrary one to have as a principal god, we should remember that Zeus, the main god of the Ancient Greeks, famously carried a lightning bolt. We should also remember that Greek legend has him disguised as a bull when he rapes the goddess Europa and takes her to Crete (and her grandson is the Minotaur). It isn't hard to see how the word for the storm god, Tarhunt, became the ancient Greek word for bull: Taurus.