Why is the crusade 3 called the kings crusade?

The first crusade was led by princes from France, though it initially included Frederick Barbarossa, King of Prussia, his army returned home following his death en route to Palestine. The french nobles successfully conquered the Levant and established the Kingdom of Jerusalem composed of four principalities. The second crusade was intended to defend the now established Kingdom of Jerusalem from the Muslim army of Saladin, a reaction to the Christian invasion and ensuing abuses. Neither Saladin, nor the Christian defenders of Jerusalem were 'Kings' of any Kingdom, as the leper-king who had ruled the Christian kingdom of Jerusalem had recently died. The Third Crusade, however, was fought between Saladin, now sultan (king) of Egypt and Syria on the one hand, and Richard I 'the Lionheart' of England.