An invasion, often referred to as an incursion, is a military action where armed forces enter a territory with the intent to occupy or control it. This can occur during conflicts between nations or groups, and it typically involves significant troop movements and strategic planning. Invasions can lead to changes in political power and territorial boundaries. Invasions can be motivated by various factors, including territorial disputes, resource acquisition, or ideological differences. Historical examples include the Norman Conquest of England in 1066 and the Iraq War in 2003. The consequences of invasions can be profound, affecting civilian populations and international relations.