Of all the Greeks, the Thessalians were considered to be the very best riders available. This isn’t surprising, as the central region of Thessaly, with its rolling plains, was abundant with large, fine horses - ideal for use in war. This caused the human population to naturally gravitate towards husbandry and horsemanship. They were also incredibly warlike, believing themselves descended from Herakles; their almost-feudal society, ruled by kings from the leading Thessalian noble families, dominated its neighbours. Like the larger Macedon to the north, Thessaly’s terrain made it an ideal cavalry training ground. As a result, cavalry became an integral part of the Thessalian martial way and gave them a distinct advantage over many of their opponents. Thessalian horsemen were a daunting prospect to face, their (at the time) innovative use of a rhomboid or diamond formation enabled them to smash through the rear and flanks of enemy phalanxes, causing death and disorder that was difficult for such a tightly-packed unit to recover from.
