Janko also points out the absurdity of calling it a Greco-Macedonian army when there was well-known enormous hatred between Greeks and Macedonians. Arrian wrote "Very heavy fighting started. Darius' Greeks were fighting purposefully to push the Macedonians back to the river and to take the position of their own left wing who had started to retreat...The clash was much more bitter thanks to the old classical rivalry between Greeks and Macedonians."