Final answer:
The events at Runnymede where the Magna Carta was agreed upon marked the beginning of constitutional governance by establishing the rule of law, even for kings, in England. This greatly influenced the development of modern democracies and the concept of justice worldwide, while also shaping the rivalry and colonial ventures of England and France into the New World.
Step-by-step explanation:
The events at Runnymede in 1215 had profound effects on England and the concept of governance worldwide. This is where King John of England agreed to the Magna Carta, which addressed the grievances of the English nobility, who were upset by the King's methods to finance his military campaigns, especially losing Normandy to France and the heavy taxation burdens placed on them.
The Magna Carta laid down the principle that the King was not above the law, establishing the foundation for the rule of law in England. This principle has had lasting global implications, forming the cornerstone of constitutional law in numerous countries and influencing the development of modern democratic principles. The idea that all, including the sovereign, were subject to the law was revolutionary at the time and essential for the development of future governance systems.
In the larger picture, the political turmoil and the changes brought by the Magna Carta and subsequent conflicts like the Hundred Years' War led to the strengthening of the English Parliament and the development of a representative government. These changes contrasted with France's path towards a strong monarchy. Over time, both England and France solidified as nation-states and carried their rivalry into the colonial era, shaping much of the modern political world.