Egyptian metallurgists established an outpost at Buhen near the present-day Sudanese-Egyptian border to smelt copper ores from Nubia around 2600-2300 BCE. Archaeological evidence at Kerma includes a bronze casting furnace dated to approximately 2300-1900 BCE. This technology transfer enabled the later Kerma civilization to develop bronze production capabilities, providing weapons and artifacts for their rulers. The introduction of copper metallurgy facilitated expanded trade networks in Northeast Africa.