In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

Let me give you an example: what is the first event mentioned?, Context: The Russian Revolution is the series of revolutions in Russia in 1917, which destroyed the Tsarist autocracy and led to the creation of the Soviet Union. Following the abdication of Nicholas II of Russia, the Russian Provisional Government was established. In October 1917, a red faction revolution occurred in which the Red Guard, armed groups of workers and deserting soldiers directed by the Bolshevik Party, seized control of Saint Petersburg (then known as Petrograd) and began an immediate armed takeover of cities and villages throughout the former Russian Empire.
The answer to this example can be: Russian Revolution
Here is why: This is a good example, and the Russian Revolution is the first event mentioned.

OK. solve this:
Who was John's rival?, Context: After his coronation, John moved south into France with military forces and adopted a defensive posture along the eastern and southern Normandy borders. Both sides paused for desultory negotiations before the war recommenced; John's position was now stronger, thanks to confirmation that the counts Baldwin IX of Flanders and Renaud of Boulogne had renewed the anti-French alliances they had previously agreed to with Richard. The powerful Anjou nobleman William des Roches was persuaded to switch sides from Arthur to John; suddenly the balance seemed to be tipping away from Philip and Arthur in favour of John. Neither side was keen to continue the conflict, and following a papal truce the two leaders met in January 1200 to negotiate possible terms for peace. From John's perspective, what then followed represented an opportunity to stabilise control over his continental possessions and produce a lasting peace with Philip in Paris. John and Philip negotiated the May 1200 Treaty of Le Goulet; by this treaty, Philip recognised John as the rightful heir to Richard in respect to his French possessions, temporarily abandoning the wider claims of his client, Arthur.[nb 4] John, in turn, abandoned Richard's former policy of containing Philip through alliances with Flanders and Boulogne, and accepted Philip's right as the legitimate feudal overlord of John's lands in France. John's policy earned him the disrespectful title of "John Softsword" from some English chroniclers, who contrasted his behaviour with his more aggressive brother, Richard.
Answer:
Arthur