Final answer:
The king retained executive and ceremonial powers after the Magna Carta, but his power to rule without consultation was limited. The importance of the retained powers is that they laid the groundwork for a constitutional monarchy and the rule of law, including trial by jury and due process.
Step-by-step explanation:
After the sealing of the Magna Carta in 1215, the king's powers were significantly limited compared to prior. However, the king maintained some essential functions such as the right to rule the kingdom, albeit under the new constraints that required consulting the nobles before making decisions, such as imposing taxes. This was a substantial reduction in the arbitrariness of royal decrees and a step towards a representative government. The monarch still held the ceremonial and executive roles but was now subject to the law.
The powers that remained with the king were important because they represented the beginnings of constitutional monarchy, which laid the foundation for modern democratic principles. The Magna Carta established the precedent that the monarch was not above the law and introduced the concept of trial by jury and due process, which are cornerstones of the Western legal system today. This watershed document also led to the development of Parliament, further restraining monarchical powers and shaping the political landscape of England.