Hey.

Don't be confused by the seemingly arbitrary borders of Europe. You are basically correct, they are arbitrary.

There's no real geographical reason to separate Europe from Asia. Most conventional definitions end Europe at the Ural and Caucasus mountains, which are kind of a physical border, but between those mountain ranges there is a large stretch of flat land between Russia and Kazakhstan.

So there isn't any geographical reason for Europe to be where it is. But also means that you can't argue using geographical reasoning that Anatolia is a part of Europe. The fact that there are regions further east in Anatolia is irrelevant because Europe is defined only by convention.

This convention had to come from somewhere. From 450 BC we have evidence that the Greeks placed Anatolia (As Asia Minor), in Asia. According to Herodotus' Histories, the three continents of the world are Asia, Europa, and Libya, and they are all defined by bodies of water. The border between Asia and Libya (Africa), was not the narrow isthmus of Suez as it is today, but the Nile. Europa was separated from Asia by one of two rivers, the Rioni and Don, but cartographers apparently debated over which.

Now Herodotus doesn't actually mention which continent Anatolia belongs to, but by inference we assumed that the Sea of Marmara formed the other boundary between Europa and Asia.

I should mention that this distinction doesn't have the negative connotations we have today of Europe vs. Asia. Herodotus himself lived in Caria, and many Greeks lived in other regions of Anatolia. There were as many barbaroi in Europa as there were in Asia. The distinction also has nothing to with the modern Turk-Greek relationship, there were no Turkic-language speaking groups living anywhere near Anatolia in 450 BC.

Cyprus is a weird case. I can't think of any historical precedent for including it in Europe. Functionally speaking, Cyprus is in the European Union and so gets included on coins and maps of the EU more often.