The Great Heathen Army was a coalition of Norse warriors, primarily from Scandinavia, that invaded England in the late 9th century. Formed around 865 AD, it aimed to conquer and settle in the region, responding to earlier Viking raids. The army was led by notable figures such as Ivar the Boneless and Halfdan Ragnarsson. The invasion marked a significant period in Anglo-Saxon history, leading to numerous battles against various kingdoms, including Mercia and Wessex. The Great Heathen Army played a crucial role in the establishment of Viking control over parts of England, influencing the culture and politics of the time.