For the earliest fortifications, see Lawrence H. Keeley, War Before Civilization (New York: Oxford University Press, 1996), and Arther Ferrill, The Origins of War (London: Thames and Hudson, 1985). For siege warfare in biblical times, see Yigael Yadin, The Art of Warfare in Biblical Lands in the Light of Archaeological Discovery (London: McGraw-Hill, 1963).


Good examples of early gates can be found at Abydos in Egypt (29th century B.C.E.) and at Troy II (early third millennium B.C.E.). See Alexander Badawy, Architecture in Ancient Egypt and the Near East (Cambridge: MIT Press, 1966), p. 57; and Yadin, Warfare in Biblical Lands, p. 57.


See David Ussishkin, The Conquest of Lachish by Sennacherib (Tel Aviv: Tel Aviv Univ. Institute of Archaeology, 1982), for a description of the remarkable archaeological evidence of the siege of Lachish.


See Thucydides’s Peloponnesian War, books 6 and 7, for his famous narrative of the Sicilian expedition.


The best ancient source on Alexander the Great is the second-century C.E. Roman historian Arrian, who used the work of Ptolemy, one of Alexander’s generals, as a source.