You can remain calm PJ. You WILL be king as your brother is so much into warfare that he will spend more time there than in his own country and will ultimately die from it. Not like it will do you any good. Because you will be too stupid to take a longer but saver way around the swampy tidewater region known as the Wash you will loose most of your crown-jewels in a spring-tide and die a couple of days later from the shock...
At least you will, however involuntarily, sign the Magna Carta thereby doing more to improve the lives of some people in England than your famous brother ever did though you won't be recognized much for it. Gee, it can be frustrating to know the future when your main concern are some petty highway men!