Ambitious rulers first brought groups of adjacent mueang together inconfederations. In the hills, these khwaen were formed by linking togetherthe mueang in successive basins along one river. The ruler often sent hissons or other relatives to rule over the defeated mueang. He captured orattracted artisans with the skills to make his own mueang more splendid andfamous than the others. He often patronized Buddhism, which enjoyed asurge of urban popularity in this era. Buddhism had originally come to theChao Phraya basin by the 5th century, but in a package of Indic gods thatwas probably not clearly defined into separate sects and traditions. In the13th century, monks again brought the Theravada Buddhist tradition fromSri Lanka and, according to the religious chronicles, it spread like wildfireon a wave of popular enthusiasm. Rulers patronized the construction ofsplendid temples, venerated monks with a reputation for learning, and collected relics and images of the Buddha, which were seen as concentrationsof spiritual power.