It's late spring of the year 1214. Due to his ever increasing power, French King Philip Augustus pushes his neighbours into forming an alliance against France, resulting in two formidable armies invading Philip's domain, on two separate fronts. English King John Lackland together with his nephew Emperor Otto march to reclaim the Angevin dominions in France and subdue the French King. The war that follows will irrevocably change the political landscape of Western Europe and alter the very course of history. It is the beginning of the XIII century. The Kingdom of France is ruled by the fair and capable Philip II, aptly nicknamed, Augustus, by his supporters. Twenty years had passed since his coronation, and Philip came a long way from emerging ruler of feudal France, becoming a major figure of the political stage that was medieval Europe. Throughout the years he waged internal wars to subdue some of his disobedient vassals, who were often stronger and more influential than their sovereign. Philip also tried to involve himself in English internal affairs, as one of his primary goals was to diminish the English presence on the continent of Europe. He acted against King Henry II and later his son, Richard the Lionheart, renowned crusader and cruel, yet very talented, soldier. The latter was an equal to Philip as an opponent, yet Richard's accidental death in 1199 temporarily halted the hostilities between the two kingdoms. As Richard didn't leave a legitimate heir, the English crown passed to his brother, John Lackland, whom Philip supported for many years, at first against his father, Henry, and later against his brother. John's ascension to the English throne was good news for Philip. He was aware that the new neighbouring monarch was quite unpopular among his people and couldn't really compare to the deceased Richard. Though initially friendly, Philip soon realized the inherent weaknesses of the new English ruler, and began using his political talents and superior military position to strip John of his dominions in northern France. As a result, by 1204, prominent Angevin duchies and counties including Normandy and Brittany fell within Philip's sphere of influence, and he soon made efforts to strengthen his control over these territories. Of course John didn't give up and after reforming his military in 1205, he invaded France a year later in order to reclaim at least some of the lost regions. Though his campaign started well, as he managed to capture the city of Angers, the brief conflict ended in a stalemate. Eventually, the French forced to sail back to England. A truce period followed, which John used to modernize the English navy and gather resources for another planned assault on Northern France. But let's stop here for a while and turn our focus to the East and the lands of the Holy Roman Empire. As early as the beginning of the XII century it was an arena of indirect rivalry between Kings of England and France, as the Germans were yet to become a major player in their on-going conflict. Long story short, following the death of the emperor, Henry VI, ten years earlier, two pretendents to the imperial throne emerged, Henry's brother Philip of Swabia of the Hohenstaufen dynasty supported by the French, and Otto of Brunswick of the Welf dynasty supported by the English. Both crowned themselves as King of the Romans, and fought each other for domination, until Philip was murdered while attending the wedding of his niece in Bamberg in 1208. Most likely Otto wasn't involved in Philip's death, yet he seized the advantage and soon ascended the imperial throne. This presented a whole new opportunity for John of England. Though Otto was still busy dealing with strong opposition in Germany, he eagerly allied himself with his uncle John against the rising power of Philip Augustus, as the King of France still supported Otto's enemies within the Empire. But while John forged alliances against Philip in the East, the French king was finishing fleet preparations for a planned invasion of England. Though John was being kept busy with internal problems, he swiftly thwarted the French invasion plans by suddenly assaulting Philip's ships harboured in Flemish ports using his reinforced navy. The English King hoped to keep the momentum going, yet impending baronial unrest forced him to postpone the planned war campaign in Northern France to the following year. John managed to temporarily appease the English nobility in late 1213 and landed with his troops in La Rochelle at the beginning of February, the next year. Philip assembled an army and marched south to repel the invasion. But soon he was informed about the unexpected second attack, led by Emperor Otto through Flanders. The situation looked grim for Philip. Moreover, the Count of Flanders together with other nobles of bordering counties sided with John's alliance and complemented the imperial army with their own forces. Fortunately, the invading armies failed to coordinate their attacks, which allowed the French King to divide his army, in an attempt to defend both fronts. While Philip's son Louis was given the uneasy task of stopping John's progress with troops his father had left him, Philip rushed back north to engage Otto's army. He reached Flanders in late July, just in time to find that his opponents had finished mustering their forces. Philip's advisors feared an open encounter with the stronger imperial army, and advised playing for time. Back in the Middle Ages, pitched battle between two large armies was regarded as a very risky solution, which could often result in a sudden and significant shift in power. King Philip heeded their council and initially hesitated, but eventually took up the gauntlet and moved his troops northward, seeking a suitable plain for cavalry manoeuvres. Otto was surprised when he learned of the French position, yet seeking battle, he marched to meet them. The opposing forces met on a plain east of Bouvines town and began deployment. We don't know exactly how many soldiers Philip fielded, but modern estimates give him around five to six thousand infantry and a little more than one thousand mounted knights. While the composition of the allied forces was roughly similar to the French, Emperor Otto had more men at his disposal, possibly just under ten thousand soldiers in total. The battle started with skirmishes on Philip's right flank, where French and Flemish knights charged at each other. Soon, Otto sent the centre of his main line forward and proper battle ensued. It was an even fight, as neither side was significantly stronger. While the Burgundy and Champagne contingents slowly pushed the Flemish flank back, English knights on the other side of the battlefield charged and gradually gained an upper hand fighting Philip's left. Otto sent some of his reserve units to aid the Flemish on his left, but it was his right flank where the first signs of trouble started to appear. Unexpectedly, despite pushing and winning his engagement, William, Earl of Salisbury charged too far into the enemy line and was surrounded and seized by the French. Upon realizing that their commander was captured, the bulk of the English cavalry fled the battlefield. In the meantime, the majority of Otto's left flank retreated due to losses, and while the battle still raged, the odds tipped towards the French side. Eventually, he saw that the enemy's advantage was becoming insurmountable and retreated as well, narrowly escaping the battlefield using the help of Saxon knights. Philip's troops prevailed and won the battle. While infantry casualties were more or less even on both sides, many of Otto's knights were killed or captured. The battle was a huge success for Philip Augustus, not only because he killed many enemies in the course of battle, as losses were roughly equal, but predominantly because he managed to capture many important nobles, including Earl of Salisbury and the disobedient Counts of Flanders, Boulogne and Lorraine. The far reaching consequences of the Battle of Bouvines soon took root. Hearing that Otto had lost, King John Lackland retreated back to England and was forced to face the unrests among the enraged English nobility, brought on by the King's failures. Soon the discontented barons revolted and England plunged into civil war, which eventually forced John to sign The Great Charter of the Liberties, limiting royal authority. But, well, that's another story. It was a tough time for Emperor Otto as well, who only held the imperial throne for one year after the battle. He became increasingly unpopular and eventually was compelled to abdicate. Philip on the other hand, used the Bouvines victory to boost his royal authority and vastly extended his sphere of influence. After his death, eight years after the battle, it was apparent that forty years of his efficacious and just rule virtually transformed a mediocre feudal state into a leading European Kingdom, which from that point on constantly played the first fiddle in European politics.