the coast, cutting off northern Israel in Galilee from Samaria and Judea.  Here Gideon turned back the incursions of the Midianites or western Arabs.  Here was the open road for Assyrians, Egyptians, for Greek armies under Antiochus, and Roman armies under Pompey, Mark Antony, Vespasian and Titus.  Hither came the Saracens from the east in 634 A. D. to rout the Greek army, and later the Crusaders from the west, to secure with castle and fortress this key to the Holy Land.  Finally, hither came Napoleon from Egypt in 1799 on his way to the Euphrates.[1234]

[Sidenote:  Geographic factors in the historical importance of passes.]

The historical importance of passes tends to increase with the depth of the depression, since the lowest gap in a range relegates the others to only occasional or local use; and with their rarity, in consequence of which intercourse between opposite slopes is concentrated upon one or two defiles.  The low dips of the Central American Cordilleras to 262 feet (80 meters) at Panama, 151 feet (46 meters) in the Nicaraguan isthmus, and 689 feet (210 meters) at Tehuantepec, present a striking contrast both orographically and historically to the South American Andes, where from the equator to the Uspallata or Bermejo Pass (12,562 feet or 3842 meters) back of Valparaiso, a stretch measuring 33 degrees of latitude, the passes all reach or exceed 10,000 feet or 3000 meters.  The southern or Pennine range of the Alps, stretching as a snow-wrapped barrier from Mont Blanc 90 miles to the central Alpine dome of the St. Gotthard, is notched only by the Great St. Bernard and Simplon passes, which have therefore figured conspicuously in war and trade, since very early times.  The Pass of Thermopylae, as the only route southward along the flank of the Pindus system, figures in every land invasion of Greece from Xerxes to the Greek war of independence.  All movements back and forth across the Caucasus wall have been confined to the Pass of Dariel and the far lower Pass of Derbent, or Pylae Albaniae; of the ancients, which lies between the Caspian and the last low spurs of the mountains as they drop down to the sea.  The latter, as the easier of the two passes, has had a longer and richer history.  It alone enabled the ancient Persians temporarily to force a wedge of conquest to the northern foot of the Caucasus, and it has been in all ages a highway for peoples entering Persia and Georgia from the north.  It has so far been the only practicable route for a railway from the Russian steppes to the southern base of the Caucasus.  While Vladicaucas and Tiflis have direct connection by the military highway over the Pass of Dariel, the railroad between these two points makes a detour of 300 miles to the east.

[Sidenote:  Intermarine mountains.]