1. The question asks: Who was the top leader in the land with the feudal system? 2. The feudal system was a social and political structure in medieval Europe where land was held in exchange for service and loyalty. 3. The top leader in this system was the king, who granted land to nobles in return for military service and loyalty. 4. Other options like prime minister, dictator, president, and serf do not fit the historical context of the feudal system. 5. Therefore, the correct answer is **The king**.