The Greek word for cavalry, hippeis was a term for one of the wealthier classes of a Greek polis. There were four classes of wealth in Athens: at the very top were the Pentekosiomedimnoi (those whose income was at least 500 units of produce), followed by the Hippeis (300-500 units), and together these made up the upper-classes, both the aristocracy of the 'old families' and the neoplouteis (nouveau riche). Then came the Zeugitai (200-300 units), which were the 'middle-class' and served as hoplites or marines. Finally came the Thetes, the poorest class, who were the rowers of the triremes and fought as skirmishers on land.
Because such a majority of our evidence comes from Athens, I will focus on Athenian cavalry, although much that is true of the Athenians applies to the cavalry of other poleis.
Greece was a land dominated by endemic war, political power in the state went to those who were the primary warriors of the polis. Before 700 BC the aristocracy ruled the state, and cavalry, and chariots, were the essential arm of the military. Then some time in the 8th or 7th century BC the hoplite class, became the most important part of the military in Greece with the development of hoplites fighting in phalanx formation probably in Argos. These expanded their dominance of the battlefield to their political world and became the leading political class. Although they still often chose members of the aristocracy to be their chief magistrates.
We first hear of a force of 400 Spartan cavalry being raised in 424 BC but they were a poor lot, the horses belonged to the richest and were only given to their riders when mobilized also the riders were usually the weakest available and were probably from the class of 'inferiors' since the line of battle was the right place for a Spartaite. Lacedaemonians cavalry were also present at Mantinea in 418 BC when they were to be arranged in 6 mora of 100 each. Agesilaus II raised and trained a force of mercenary cavalry while he was in Asia and it was these that worsted the Thessalian horse in 394 BC, The Thessalians being looked upon as the best cavalry of that time. By the time of Laecheum in 390 BC the performance of the Spartan cavalry had once more reverted to be inadequate at best in that engagement. Agesilaus in his Boeotian campaign of 377-376 BC is said to have used a force of 1,500 mercenary cavalry. At Leuctra Cleombrotus had no mercenary horse and his native Spartan cavalry which was soundly defeated by the Thebans.
The first thing to bear in mind when looking at Greek cavalry, and indeed most Greek military forces of any kind, is that they were essentially a citizen militia. There was no 'soldier' profession; any citizen (and in some cases other sections of the populace, for example the metiokoi (resident foreigners) in Athens, and the perioeci (dwellers around) and helots in Sparta) between the ages of about eighteen and sixty could be called up for a campaign or battle.
In the case of the cavalry of most Greek polis, however, the hippeis were volunteers from within the richer citizen segment. To be considered a member of the upper classes in most states was a measure of wealth, and this would include both the aristocracy of the old families as well as the nouveau riche of the merchant classes.
The main source for the actual organization of ancient Greek cavalry is Xenophon, who wrote both a treatise on horsemanship (Peri Hippikes) and a manual written for the commander of the Athenian cavalry (Hipparchikos).
Athens' hippeis were augmented by two separate corps, the hippotoxitai and the hammipoi. The hipppotoxitai were horse archers. These numbered two hundred men, and they appear to have been present from the 440s until some time in the first half of the fourth century. They were Athenian citizens (Alcibiades the younger served with them in 395 BC. The Hammipoi were lightly armed infantry trained to fight alongside the cavalry.
The Boeotians had adopted hammipoi by 418 BC, and the Spartans were using them by 395 BC these were the Sciritis an Arcadian perioicic community who were persuaded to give up their hoplite arms and instead fight alongside the cavalry. After Leuctra the Sciritis became independent and thus Spartan cavalry at Mantinea in 362 fought without their support. By 365 BC, the Athenians had supplemented their basic cavalry force with a corps of hammipoi , and the Argives had done the same by the 360's . Their numbers are sometimes unclear, but in the case of the Thebans and of Gelon's troops the ratio of infantry to hippeis was 1:1.
In general it seems that the arms and armour of a hippeis varied from state to state, but also from individual to individual depending on his wealth. The cavalryman of ancient Greece carried either javelins or a lance for his main offensive arms, and sometimes both, as can be seen for example on the Panaitios relief in Athens. He also usually carried a sword as a secondary weapon.
When carrying javelins, it appears that usually two or three were carried. The javelins are sometimes shown in art with throwing loops, which were held around the fingers and gave the throw greater range and accuracy.The lance used by cavalry was about the same length as a hoplite spear, around eight feet long, and is sometimes depicted with a butt spike. Sometimes two are carried.
Throughout this period breastplates were common, although their frequency of use and type fluctuated with the times. Some cavalry is depicted with very little armour, and these may well have been prodromoi or scouts, or simply depict hippeis who preferred to fight unarmoured. Unlike hoplite breastplates, cavalry breastplates were quite often composed purely of bronze, the bell cuirass which flanged from the waist rather than the bronze linen composite cuirasses more common to the hoplites.
Greek cavalry did not commonly carry shields. There are some depictions of men mounted on horses carrying an aspis, but these may well have been mounted hoplites, although at least one of these shows the rider in combat There is also a depiction of some horsemen holding horses by the reins and armed with a pelte (a small shield, either round or crescent shaped) from about 500 ). Shields were being used earlier than is often thought in Magna Graecia the Spartan colony of Taras was using them by the fifth century as shown on two Greek coins , and there are many such representations from the fourth century.
Cavalry are very often depicted fighting hoplites in friezes and on vases, (for example the Defiles relief and the Eleusis relief), the latter often depicted in defeat. This evidence, combined with a close reading of our literary sources, reveals that cavalry often fought hoplites, and that they were frequently successful.
It is known that cavalry were able to charge and defeat already disordered hoplites as when the Megarian and Phliasian hoplites in dassaray from their pursuit of the Persians were caught by Theban cavalry at Plataea in 479 BC who killed 600 of them.
There are several examples of cavalry defeating large numbers of hoplites in good formation. In 429 BC, at Spartolos an Athenian expedition, which was composed 2,000 hoplites and 200 cavalry, was sent to Chalcidice. The Chalcidian hoplites were defeated, but their cavalry and light troops beat their Athenian opposite numbers. The Chalcidian cavalry and light armed infantry then attacked the Athenian main infantry force, forcing the Athenians back with missile fire and skirmishing tactics. Thucydides says the Chalcidian cavalry kept charging in whenever they saw an opportunity and that it was this that contributed most to the rout of the Athenians. The Athenians lost about 20% of their men.
Because psiloi and peltasts were lightly armed and fought in loose formation, cavalry was very effective against them, especially when fighting in open terrain Accounts of engagements between cavalry and psiloi or peltasts are rare because the light infantry avoided them at all costs.See Thucydides for the defeat of the Athenian psiloi by Theban horse at Megara. Xenophon mentions one case where Theban mercenary peltastswere caught by Olynthian cavalry in the open in 377 BC and heavily defeated. Theban cavalry surprised and routed Spartan mercenary peltasts in 377 BC, and again in the following year they defeated another force of Spartan mercenary peltasts at Thespiae. In the disaster the Spartans suffered at the hands of Athenian peltasts at Lechaeum in 390 BC, only those Spartans who attached themselves to their cavalry were saved, this indicating that the peltasts were reluctant to pursue those hoplites screened by cavalry.
Cavalry, due to their speed, are ideally suited to both flanking manoeuvres and to acting as mobile reserves, although the hippeis seem to have usually been deployed either on the wings or at times in front of the main army. In Thucydides' description of the battle of Delium, the Theban cavalry acts as a flanking force, taking the Athenians in the flank by surprise and thus causing their panic and defeat
The Theban cavalry pursued the defeated Athenians at Delium, though the fall of night limited the pursuit After the Athenians under Alcibiades defeated a large force of Persian cavalry in 409 BC, the Athenian cavalry and a small force of hoplites pursued them until dark. The Spartans defeated the Persian cavalry in 395 BC, and these were pursued by Agesilaus' cavalry, who also captured the Persian camp. At the 'tearless battle' of 368 BC, the Spartans defeated the Arcadians Messenians and Argives; the cavalry, with help from Dionysus' Celtic mercenaries, pursued the defeated and cut down many of them. However at Laecheum in 390 BC the Spartan cavalry failed to pursue the Athenian peltasts effectively by keeping pace with their hoplites only.