Why did Henry V invade France during the Hundred Years’ War?

Henry V invaded France in 1415 primarily to assert his claim to the French throne and to expand English territories. While he sought to reclaim lands previously ceded by the French, such as Aquitaine, he also laid claim to Normandy, Touraine, and Maine—territories that had historically been part of the Angevin holdings—as well as other regions that had never been under English control.1

Henry V appears to have genuinely convinced himself that these claims were just rather than merely a pretext for aggression. When diplomatic negotiations with the government of Charles VI failed to yield his demands, he turned to the "way of force". His military strategy was methodical, focusing on the systematic reduction of northern French towns and fortresses to establish permanent English control, rather than relying on the haphazard operations of the previous century. This ambitious policy was supported by a united nation and financed through parliamentary taxation and borrowing.1