Indeed it's him. All the time, I've been hinting you to do the most logical thing, grab the list of monarchs killed in battle from Wikipedia and run it down.
John of Bohemia, also known as John the Blind or John of Luxembourg (especially in Czech Republic, exemplifying his status as "alien king"), ascended to throne of Bohemia at age 14 as a result of marriage born from political intrigue in wake of assassination of last native Bohemian king, ousting another claimant. However, he clashed almost instantly with Bohemian nobility that had grown powerful in the interregnum and a king, raised mostly in the French court with ideas about centralized kingdom with strong monarch, wasn't to their liking. Eventually, John managed to stabilize the country somewhat by giving in to some of their demands, which lent the nobles power quite unprecedented for the time, for example king wasn't allowed to levy troops for foreign wars or extraordinary taxes without nobles' approval, and council had to ratify any subsequent new king before he could be crowned. Nevertheless, things were tense and John eventually resigned on running the country directly and left the country to travel and focus on international affairs, in which he was quite successful, expanding both Kingdom of Bohemia and his other holdings significantly by diplomatic means. Still, the kingdom went downhill in his absence, which he eventually solved by handing the reins of the kingdom to his firstborn son, who did quite well in that capacity. John lost his sight while participating in Northern Crusades, but remained quite active in political affairs until his alliance with French king led him to the battle at Crécy. According to the contemporary chroniclers, when the battle was all but lost, he gave a bit of speech about "Far be it that the King of Bohemia should run away..." and asked to be led to the melee where he made his last stand. He was succeeded as King of Bohemia by his firstborn son under regnal name Charles IV...which should be more familiar to you.
Your turn.