The model of extended gradualism, developed and proposed by Hans van Wees, is similar to gradualism, but over a much longer period of time. Van Wees backs his hypothesis up primarily with iconography on pots and Homeric poems such as The Iliad and The Odyssey.
Van Wees proposed that there is a documented, primarily in iconography, transitional form of early hoplite warfare. The most notable iconographic recording of this is on the Chigi Vase, pictured as the banner of this webpage. The Chigi Vase shows two lines of hoplites engaged in battle, with a second line of reinforcements coming to aid those on the left. The vase also depicts the normal spears, in addition to javelins. We know that missiles were something that the later hoplites didn’t carry.The armor depicted by Homer in both The Iliad and The Odyssey consists of not only a bronze breastplate, but also bronze grieves, helmets, and even spears. One line that stands out in The Iliad is:
“Then Meges struck the topmost crest of Dolops’s bronze helmet with his spear and tore away its plume of horse-hair, so that all newly dyed with scarlet as it was it tumbled down into the dust” (Homer, 297).
Remarkably, the armor resembles that found in the Argos Panoply very closely and we know that many hoplites did have crests on their bronze helms.
Tyrtaios, a Spartan poet from the 7th century BC, suggests that a transitional form of the phalanx existed in his era. Unfortunately, only ~250 of his lines survived to this day, but in them it describes elements of phalanx warfare that survived and some elements that didn’t. One passage states:
“…[Let us, then] go forward behind our hollow shields like [a flight of locusts]… Each tribe severally brandishing its man-slaying ashen spears…” describe elements of the phalanx we are familiar with. However, he also describes elements that could have been weeded out over time. An example of this would be, “…will they draw back for the pounding [of the missiles, no,] despite the battery of great hurl-stones, the helmets shall abide the rattle [of war unbowed]” (Tyrtaios, Fragment 1).
In later texts and battle accounts, there is no mention of the heavy hoplite troops carrying slings or even missiles of any sort.
Extended gradualism offers a very probable explanation for the evolution of hoplites and phalanx warfare. It uses some evidence that is solid (iconography) and some that is ambiguous (Homeric poems), which means it has both its strengths and weaknesses. Perhaps its greatest strength lies in the words of a poet that was alive during a time when these transitions were being undergone and just about concluding, Tyrtaios. Many scholars and historians believe that this is the explanation and that its evidence is the most trustworthy and telling.