The flooding of the Nile has been an important natural cycle in Nubia and Egypt since ancient times. It is celebrated by Egyptians as an annual holiday for two weeks starting August 15, known as Wafaa El-Nil. It is also celebrated in the Coptic Church by ceremonially throwing a martyr's relic into the river, hence the name, The Martyr's Finger. The flooding of the Nile was poetically described in myth as Isis's tears of sorrow for Osiris when killed by his brother Set.

The Nile is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest river in the world, though this has been contested by research suggesting that the Amazon River is slightly longer. Of the world's major rivers, the Nile is one of the smallest, as measured by annual flow in cubic metres of water. About 6,650 km (4,130 mi) long, its drainage basin covers eleven countries: the Democratic Republic of the Congo, Tanzania, Burundi, Rwanda, Uganda, Kenya, Ethiopia, Eritrea, South Sudan, Sudan, and Egypt. In particular, the Nile is the primary water source of Egypt, Sudan and South Sudan. Additionally, the Nile is an important economic river, supporting agriculture and fishing.