Dodekaschoinos

The Triakontaschoinos (Greek: Τριακοντάσχοινος, "Land of the Thirty "Schoinoi"), Latinized as Triacontaschoenus, was a term used in the Greco-Roman world for the part of Lower Nubia between the First and Second Cataracts of the Nile. In the Ptolemaic and Roman periods, all or the northern part of this area, known as the Dodekaschoinos (Δωδεκάσχοινος, "Land of the Twelve Schoinoi"), Latinized as Dodecaschoenus, was often annexed to Egypt or controlled from it.

In 275 or 274 BC, Ptolemy II (r. 283–246 BC) sent an army to Nubia, and defeated the Kingdom of Kush. The expedition pursued several objectives: on the one hand, it curbed Kushite power, which had been steadily expanding for the past century, and helped secure Ptolemaic rule against the native Egyptians of Upper Egypt, who might be tempted to seek Kushite aid in their revolts. In addition, the expedition secured the Ptolemies' control of the supply route for African elephants, which played a crucial role as war elephants in their conflicts with the rival Seleucid Empire, that monopolized access to the larger Indian elephants. As a result of this campaign, the area between the First and Second Cataracts of the Nile, which also included the valuable gold mines of the Eastern Desert, was annexed to Egypt and became later known as Triakontaschoinos.

...
Wikipedia