Following the An Lushan rebellion the diplomatic exchange between Buddhist Indian kingdoms and the Tang dynasty all but ceased. Prior to the battle of Talas, between 640 and 750 diplomatic envoys from Indian kingdoms, often accompanies by Buddhist monks, had regularly visited the Tang court. Military cooperation with Indian kingdoms was considered by the Tang court in the late 8th century, but diplomatic relations were only fully resumed by the Song dynasty. The increasing Muslim dominance of these Silk Roads made it more difficult for Buddhist monks and pilgrims to travel between India and China. Chinese Buddhism developed into an independent religion with distinct spiritual elements. Indigenous Buddhist traditions like Pure Land Buddhism and Zen emerged in China. China became the center of East Asian Buddhism, following the Chinese Buddhist canon, as Buddhism spread to Japan and Korea from China.