The nobility continued to be the most important social class, with much the same differences of grade among themselves, the same authority and privileges, and the same tendencies to war against the king and with one another and to commit acts of violence and robbery as in the preceding period. The conflict of the nobility as a class against the king took definite shape, and a numerous new nobility, the _caballeros_ (knights), sprang up. The _caballeros_ proceeded from the plebeian ranks, being composed of those who could equip themselves for war as cavalrymen. Although they gained certain privileges, such as exemptions from taxation, thus weakening the king’s power, they served in fact as a counterpoise to the hereditary noble class. They were much favored by the kings, who needed well-equipped soldiers for their wars. The clergy made distinct gains as regards personal immunities and the freedom of their lands from the usual obligations, especially from that of taxation. This bettering of their position was not the result of general laws, but rather of the accumulation of individual privileges, granted now to one religious institution, now to another. Their advantages in these respects were not always well received by others, and objections were made, especially by the popular element, through their representatives in the national _Cortes_ (Congress, or Parliament),--of which institution presently. [Sidenote: The advance of the middle class.] [Sidenote: Gains of the servile classes.]