One of the most effective and enduring military formations in ancient warfare was that of the Greek phalanx. The age of the phalanx may be traced back to Sumeria in the 25th century BCE, through Egypt, and finally appearing in Greek literature through Homer in the 8th century BCE (and since has been generally associated with Greek warfare strategy, the name itself coming from the Greek word for 'finger'). The phalanx formation was a close-rank, dense grouping of warriors armed with long spears and interlocking shields.
This is a companion discussion topic for the original content at https://www.worldhistory.org/article/110/the-greek-phalanx/.