The Nile River is conventionally identified as the world’s longest river.
The Nile flows northward for roughly 6,650 kilometres from the Lake Victoria region and other headwaters to the Mediterranean Sea. Its two principal tributaries are the White Nile and the Blue Nile; they meet at Khartoum in Sudan before the river continues through Egypt.
The Nile’s status is sometimes debated because measuring the source and mouth of a river can produce different results. Some studies argue that the Amazon may be longer depending on which distant headwater is selected. Standard geographical references nevertheless traditionally rank the Nile first. Its annual flood, historically driven mainly by the Blue Nile, supported dense settlement and agriculture in ancient Egypt, while the Aswan High Dam now regulates much of the flow.