The Suez Canal was viewed as the "Lifeline of the Empire" because it allowed Britain quicker access to its colonies in Asia and Africa.
The Suez Canal.
provided a strategic shipping route to British colonies.
By travelling through the Suez Canal, shipping no longer had to transverse the whole of the continent of Africa- shortening the journey to India and the Far East by several days.
because they had Suez Canal
The Suez Canal connects the Mediterranean Sea and the Gulf of Suez. This typically would have been dug by hand, but the canal utilized new steam technology and dredging systems to create the canal. When Egypt took over the Suez Canal Company, it marked the end of the British Empire's control on the area.
The British actually finished the Suez Canal, even though the French started building it.
That's kind of a subjective question, but in my mind it was in 1956 when Egypt took the Suez Canal away from the British. When India threw the British out.
Sudan was part of the main shipping route to the East. Britain needed to control the Suez Canal.
Most canals were built after the Roman Empire split, for example the Suez Canal, the Panama Canal, and the Erie Canal.