Why were noble people interested in military campaigns?

This state of affairs can be explained by the fact that such military campaigns were a source of profit for the nobility, especially if the campaign was successful. In general, in ancient times, war was in the interests of the nobility. Then the rulers always counted on the support of the nobility, who could also finance the military campaign. The ruler received glory and honor, and the nobility received new lands, as well as an influx of new slaves.