Around the 8th century BC, ramming began to be employed as war galleys were equipped with heavy bronze rams. Records of the Persian Wars in the early 5th century BC by the Ancient historian Herodotus (c. 484-425 BC) show that by this time ramming tactics had evolved among the Greeks. The formations could either be in columns in line ahead, one ship following the next, or in a line abreast, with the ships side by side, depending on the tactical situation and the surrounding geography. There were two primary methods for attack: by breaking through the enemy formation ("diekplous") or by outflanking it ("periplous"). The "diekplous" involved a concentrated charge in line ahead so as to break a hole in the enemy line, allowing galleys to break through and then wheel to attack the enemy line from behind. The "periplous" involved outflanking or encircling the enemy so as to attack them in the vulnerable rear or side by line abreast. If one side knew that it had slower ships, a common tactic was to form a circle with the bows pointing outwards, thereby avoiding being outflanked. At a given signal, the circle could then fan out in all directions, trying to pick off individual enemy ships. To counter this formation, the attacking side would rapidly circle, feigning attacks in order to find gaps in the formation to exploit.