The Greek style of warfare had been honed over the preceding centuries.[164][165] It revolved around the hoplite, members of the middle-classes (the zeugites) who could afford the armour necessary to fight in this manner.[166] The hoplite was, by the standards of the time, heavily armoured, with a breastplate (originally bronze, but probably by this stage a more flexible leather version), greaves, a full helmet, and a large round shield (the aspis).[165] Hoplites were armed with a long spear (the doru), which was evidently significantly longer than Persian spears, and a sword (the xiphos).[165] Hoplites fought in the phalanx formation; the exact details are not completely clear, but it was a close-knit formation, presenting a uniform front of overlapping shields, and spears, to the enemy.[164] Properly assembled, the phalanx was a formidable offensive and defensive weapon;[167][168] on occasions when it is recorded to have happened, it took a huge number of light infantry to defeat a relatively small phalanx.[167] The phalanx was vulnerable to being outflanked by cavalry, if caught on the wrong terrain, however.[169] The hoplite's heavy armour and long spears made them excellent troops in hand-to-hand combat[165] and gave them significant protection against ranged attacks by light troops and skirmishers. Even if the shield did not stop a missile, there was a reasonable chance the armour would.[165]