Amitābha (अमिताभ, IPA: ɐmɪˈtaːbɦɐ), also known as Amitāyus, is the primary Buddha of Pure Land Buddhism. In Vajrayana Buddhism, he is known for his longevity, discernment, pure perception, purification of aggregates, and deep awareness of emptiness. He possesses infinite merit resulting from good deeds over countless past lives as a bodhisattva named Dharmākara.
According to the Larger Sūtra of Immeasurable Life, Amitābha was, in very ancient times and possibly in another system of worlds, a monk named Dharmākara. In some versions of the sūtra, Dharmākara is described as a former king who, having come into contact with Buddhist teachings through the buddha Lokeśvararāja, renounced his throne. He then resolved to become a Buddha and to create a (literally "buddha-field", often called a "Pureland" or "Buddha Land": a realm existing in the primordial universe outside of ordinary reality, produced by a buddha's merit) possessed of many perfections. These resolutions were expressed in his forty-eight vows, which set out the type of Pureland Dharmākara aspired to create, the conditions under which beings might be born into that world, and what kind of beings they would be when reborn there.
In the versions of the sutra widely known in China, Vietnam, Korea and Japan, Dharmākara's eighteenth vow was that any being in any universe desiring to be reborn into Amitābha's pure land () and calling upon his name with sincerity, even as few as ten times will be guaranteed rebirth there. His nineteenth vow promises that he, together with his bodhisattvas and other blessed Buddhists, will appear before those who, at the moment of death, call upon him. This openness and acceptance of all kinds of people has made belief in pure lands one of the major influences in Mahāyāna Buddhism. Pure Land Buddhism seems to have first become popular in Gandhara, from where it spread to China infused with Taoists and Confucian philosophy before spreading to Central and East Asia.