There's a TON of historical context in the various major iterations of the King Arthur legend, since the varying elements of his exploits, character, and principles reflect the qualities of the ideal hero valued by each successive generation.

In the earliest, pseudo-historical Arthurian texts such as Lawman’s Brut and The History of the Kings of Britain by Geoffrey of Monmouth, Arthur is a nationalistic hero during a time after the Norman conquest in which the people of England were searching for an identity. He then becomes a respected but tragic imperialist hero in Thomas Malory’s Le Morte d’Arthur, influenced by the civil and political unrest stemming from the dynastic War of the Roses. As we move away from medieval tales and toward the modern era, we are presented with Arthur as a Christ-like hero, reflecting the strong moral values of Victorian England in Idylls of the King by Alfred Tennyson. Finally, during the chaos of World War II and the early days of the Cold War, T.H. White’s classic The Once and Future King reveals Arthur as a politically idealist hero, struggling with the concepts of just war and proper government.

Geoffrey of Monmouth was born around 1100 AD, about 40 years after the Norman victory over the Anglo-Saxons at the Battle of Hastings. The native Britons had been largely without a true face for close to 1,000 years, having been first colonized by the Roman Empire around 43 AD, then gradually invaded by the Anglo-Saxons throughout the fifth and sixth centuries, and finally conquered by the Normans in 1066 AD. The character of King Arthur, who previously existed either as a Romano-British military leader or a perhaps a mere legend of Welsh folklore, was now given a full narrative history and a literary persona. But more importantly, Arthur gave the Britons back their identity. Additionally, Geoffrey traces the lineage of the British people back to the Trojans through Brutus, and the Normans claimed descent from the Trojans themselves. So this literary link allowed the invading Normans to see themselves as heroic and justified in overthrowing the seemingly barbaric Saxon traitors, and it also allowed native Britons to identify with their new rulers and make peace with the Norman occupation.

Next we have Thomas Malory, who lived and composed his work during the War of the Roses, as supporters of the rival houses of York and Lancaster vied for control of the throne of England, leaving the nation divided and torn. Any feelings of British nationalism in the face of foreign invasions would likely have given way to the fear and uncertainty that comes from such internal strife. So Arthur is no longer placed in the historical and generational sequence of British conquest and revolt; rather, his story is pulled out of the timeline entirely, and his fall becomes an entrance into aristocratic insecurity, providing a parallel to the intense civil war that marked England at the time. In short, Arthur becomes a tragic hero, disillusioned with his own kingship and system of values and he struggles to hold together his kingdom while it crumbles from within due to political strife and failure of his chivalric dream.

With the rise of Romanticism and medievalism in the early nineteenth century, the stories of Arthur and his knights regained a foothold in artistic and social culture. The most famous and important work from this era of Arthurian restoration was Poet Laureate Alfred Tennyson’s Idylls of the King. One of the most influential aspects of Victorian England was the religious revival sparked by the Evangelical movement; therefore, in Tennyson’s account of the legend, the king again transforms from the tragic defender of chivalry to a hero more attuned to the values of the Victorian era: a Christ-figure.

Then in 1938, T.H. White began to turn the Arthurian myth on its head, deconstructing the old legends and translating them into his thought-provoking political allegory The Once and Future King. White published his masterpiece in four stages, beginning just prior to the outbreak of World War II and culminating during the height of the Cold War. By the time the first section was completed, Adolf Hitler had abolished democracy and rearmed Nazi Germany, Benito Mussolini had turned Italy into a fascist police state, and Joseph Stalin was on his way to creating a vast socialist empire. In his attempt to contemporize the legend, White removed all traces of the idealism that came before, from Geoffrey’s idolization of military glory, to Malory’s infatuation with the chivalric code, to Tennyson’s emphasis on religious perfection. Rather than purely idealizing the hero himself, White instead turns Arthur into the idealist as he struggles to create a perfect society by searching for the balance between "might and right."