After reading about feudalism in the Middle Ages it became apparent that lords lived on their lands far away from the king and provided military services themselves in exchange for said lands. However, on many occasions they were more powerful than the king himself and held courts of their own.
My question is, are there any other courts where lords lived in the palace with the king in a similar fashion in Europe? Was this the first example of such practice? My other question is, did these lords not go to war themselves? Which is to say did they stop providing military service themselves in favor of the kingdom's armies? Also, were these nobles connected to lands (like in feudal times) and their houses, presenting problems of the area and politics to the king?