Suez Canal

The Red Sea is believed by some historians to have gradually receded over the centuries, its coastline slowly moving southward away from and the Great Bitter Lake. Coupled with persistent accumulations of Nile, maintenance and repair of Ptolemy's canal became increasingly cumbersome over each passing century.

Two hundred years after the construction of Ptolemy's canal, seems to have had no west–east waterway passage, because the  of the Nile, which fed Ptolemy's west–east canal, had by that time dwindled, being choked with silt.

By the 8th century, a navigable canal existed between and the Red Sea, but accounts vary as to who ordered its construction—either  or, or. This canal was reportedly linked to the River Nile at Old Cairo and ended near modern. A geography by Dicuil reports a conversation with an English monk, Fidelis, who had sailed on the canal from the Nile to the Red Sea during a pilgrimage to the Holy Land in the first half of the 8th century

The   is said to have ordered this canal closed in 767 to prevent supplies from reaching  detractors.

Omar
Umar, also spelled Omar (عمر بن الخطاب ʻUmar ibn al-Khaṭṭāb , "Umar, Son of Al-Khattab"; c. 584 CE – 3 November 644 CE), was one of the most powerful and influential Muslim s in history. He was a senior of the. He succeeded (632–634) as the second caliph of the  on 23 August 634. He was an expert Muslim known for his pious and just nature, which earned him the  Al-Farooq ("the one who distinguishes (between right and wrong)"). He is sometimes referred to as Umar I by historians of, since a later caliph, , also bore that name.

Under Umar, the caliphate expanded at an unprecedented rate, ruling the and more than two-thirds of the. His attacks against the Sasanian Empire resulted in the in less than two years (642–644). According to Jewish tradition, Umar set aside the ban on  and allowed them into  and to worship. Umar was eventually killed by the Persian (known as ’Abū Lu’lu’ah in Arabic) in 644 CE.

Umar is revered in the tradition as a great ruler and paragon of Islamic virtues, and some hadiths identify him as the second greatest of the Sahaba after Abu Bakr. He is viewed negatively in the tradition.

Since Medina, with a rapidly growing population, was at risk of recurring famines when crops were lacking, Umar sought to facilitate the import of grain. He ordered the building of a canal connecting the Nile to the Red Sea and an improvement of port infrastructure on the Arabian coast.