Why was control of the English Channel important to Henry V’s war plans?

Control of the English Channel was a vital strategic priority for Henry V to ensure the success of his military campaigns in France during the Hundred Years’ War.

Following his victory at the Battle of Agincourt in 1415, Henry recognized that maintaining secure lines of communication and supply across the water was essential for his goal of establishing a dual monarchy. To achieve this, he spent the year following Agincourt building a powerful fleet specifically to clear the Channel of Genoese ships that were providing naval support to the French.1

By securing the Channel, Henry protected his ability to transport troops and resources to the Continent, which allowed him to conduct the methodical, multi-year subjugation of Normandy beginning in 1417. This naval dominance was a necessary component of his broader ambition to rule kingdoms on both sides of the Channel, as it prevented French interference with his cross-channel logistics and solidified his military position in France.123