Testudo and Synaspismos

[Robert Vermaat]

The question still remains: is this the same formation, with the same distances, used by greek phalanx?

In my opinion it's not 100% the same formation but comparable. I think this is the late Roman fulcum (which some believe was also called the testudo), closed ranks with shields locked, both in a defensive as well as an offensive variant (as described in the Strategicon).

Sure, Romans fought differently from the Greek phalanx but I agree with modern scholars who propose that Romans had a number of different tactics available. One of these was the very close combat with locked shields. Mostly used for the testudo (the turtle variant for sieges) but becoming more and more common towards the Dominate and after. These later infantry formation are not the same as Hellenistic phalanxes but can be compared to them. I think that Arrian is referring to a similar formation in his treatise about how to defend against cavalry, and his description of the close-order infantry resembles that of the close-order in the testudo.

However the discussion remains wide open because apperently there is no 100% agreement about the exact meaning of the Original terminology (or whether the authors used them correctly).