The death of Alexander the Great at Babylon in 323 BC ultimately resulted in numerous struggles among his generals (despite initial attempts to maintain cohesion by Perdiccas).
Among these Successors (diodochi) Ptolemy the son of Lagos (later assuming the title of king and becoming Ptolemy I Soter), who had been assigned satrap of Egypt, was able to consolidate his position in this territory and periodically attempt to take advantage of the situation in the various conflicts which were raging in these last few decades of the fourth century. After Ipsos (301 BC) he (again) seized part of Koile Syria and captured part of south-east Asia Minor. He took over the League of Islanders in the late 290s or early 280s which had originally been founded by Antigonos Monophthalmos to control Aegean sea-routes. After ruling for 38 years in 285 BC Ptolemy promoted his son Ptolemy II, later called Philadelphos (r.285-246 BC), to the status of co-ruler, himself dying two years later (see Shipley 2000).
These Indian elephants could not be so easily replaced since control of significant parts of the Middle East and Central Asia had fallen to the Seleucids by this point. Due to frequent hostilities between the descendants of Ptolemy I and Seleucus I, the Ptolemies were effectively deprived of any significant opportunity to acquire more Indian elephants except through capture in warfare (see Casson 1993).
“Elephants, when tamed, are employed in war, and carry into the ranks of the enemy towers filled with armed men; and on them, in a very great measure, depends the ultimate result of the battles that are fought in the East. They tread under foot whole companies, and crush the men in their armour.”
Pliny NH 8.9.27 – trans. Bostock 1855.
The route running from Apollonopolis Magna (Edfu) on the Nile to Berenike on the Red Sea was of particular significance. The most recent fieldwork by the University of Michigan has shown that Edfu was connected to the Red Sea via a series of tracks along the Wadi Muyah through Bir ‘Abbad to El-Kanais, up to the Wadi Barramiyyam via Bir Abu Rahal, and Bir ‘Iayyan to Barramiyyah. These tracks also revealed square shaped cairns (stone-markers) laying out the route, though not many preserved signal or watch-towers. However a stele set up by Rhodon, son of Lysimachos, in 257 BC, appears to have been intended as a distance marker. It is located at Bir ’Iayyan 95 km east of Edfu, on the Edfu-Barramiyyam road (see Cohen 2006 and Wright 2003).