The school first became prominent with the founding of a monastery upon the top of Mount Lu by Hui-yuan in 402. It spread throughout China quickly and was systematized by Shan-tao (613-681). The philosophy spread to Japan and slowly grew in prominence. Honen Shonin (1133-1212) established Pure Land Buddhism as an independent sect in Japan, known as "Jodo Shu". Today Pure Land is the dominant form of Buddhism in Japan.
Contemporary Pure Land traditions see the Buddha Amitabha preaching the Dharma in his buddha-field (sa buddhakchetra), called the "Pure Land" (zh 净土, pinyin jing4tu3, jp jodo) or "Western heaven" (zh 西天), a region offering respite from karmic transmigration. In such traditions, entering the Pure Land is popularly perceived as equivalent to the attainment of nirvana.
In fact, the main idea behind Pure Land Buddhism is that Nirvana is no longer practical nor possible to attain in our present aeon. Instead, devotion to Amitabha will gain one enough karmic merit to go to the Pure Land (reminiscent of Heaven) from which Nirvana will be easier to attain, because in this paradise there are no negative experiences so no new negative karma is created. Existing negative karma would disappear.
Some Pure Land Buddhists have taught that, in order to be reborn in Amida's Western Paradise, the devotee should chant or repeat a mantra or prayer to Amida as often as possible to increase a proper and sincere state of mind. This fairly simple form of worship has contributed greatly to its popularity.