Indonesian Esoteric Buddhism or Esoteric Buddhism in Maritime Southeast Asia refers to the traditions of Esoteric Buddhism found in Maritime Southeast Asia which emerged in the 7th century along the maritime trade routes and port cities of the Indonesian islands of Java and Sumatra as well as in Malaysia. These esoteric forms were spread by pilgrims and Tantric masters who received royal patronage from royal dynasties like the Sailendras and the Srivijaya. This tradition was also linked by the maritime trade routes with Indian Vajrayana, Tantric Buddhism in Sinhala, Cham and Khmer lands and in China and Japan, to the extent that it is hard to separate them completely and it is better to speak of a complex of "Esoteric Buddhism of Mediaeval Maritime Asia." Many key Indian port cities saw the growth of Esoteric Buddhism, a tradition which coexisted alongside Shaivism.
Java under the Sailendras became a major center of Buddhism in the region, with monumental architecture such as Borobudur and Candi Sukuh. The capital of the Buddhist empire of Srivijaya in Palembang, Sumatra was another major center.
The decline of Buddhist states and the rise of Islamic states in the region during the 13th–16th centuries saw the steep decline of this tradition.
History
The diffusion of Esoteric Buddhism in the region began with the arrival of Indian Buddhist monks in the 7th century. These include the central Indian Atikuta (fl. 650s), the Chinese Punyodaya (fl 650s), Yijing (635-713), the South Indian Dharmaruci/Bodhiruci (d. 727), Nagabodhi, Vajrabodhi and Bianhong (the 8th century teacher of Kukai). The Chinese Buddhist monk Yijing reports that in the 7th century there was a Buddhist center in Java named Kalinga (Heling) to which Chinese monks traveled in order to study.
Another source of this Indonesian Tantric tradition was from Sri Lanka's Abhayagiri vihāra, a well known center of Vajrayana study and practice, which even established a branch monastery in Central Java in the 8th century with Sailendra patronage.
A stronghold of Esoteric Buddhism, the empire of Srivijaya (650 CE–1377 CE) patronized Buddhist monks and institutions and thus attracted pilgrims and scholars from other parts of Asia. These included the Chinese monk Yijing, who made several lengthy visits to Sumatra on his way to study at Nalanda University in India in 671 and 695, and the Bengali Buddhist scholar Atisha (982-1054 CE) who played a major role in the development of Vajrayana Buddhism in Tibet. Yijing praised the high level of Buddhist scholarship in Srivijaya and advised Chinese monks to study there prior to making the journey to the great institution of learning, Nalanda Vihara, India. He wrote:
Yijing was also responsible for the translation of a large numbers of Buddhist scriptures from Sanskrit into Chinese. He translated more than 60 sutras into Chinese such as the Golden Light Sutra. The Account of Buddhism sent from the South Seas & Buddhist Monks Pilgrimage of Tang Dynasty are two of Yi Jing's best travel diaries, describing his adventurous journey to Srivijaya and India, the society of India and the lifestyles of various local peoples.
In Java, the 8th century Shailendra dynasty promoted large scale Buddhist building projects such as Borobudur. Later central Javanese bronze and silver Buddhist images show Tantric themes such as mandalas and the Five Tathagatas.
In the 13th century Buddhism thrived in Eastern Java, the Singhasari kingdom of King Kertanegara of Singhasari patronized Vajrayana. Buddhism continued to thrive under the Hindu-Buddhist Majapahit Empire (1293–1527). Their capital Trowulan had many annual festivities for Buddhism, Shaivism, and Vaishnavism. Some of their kings were Vajrayana practitioners, such as King Adityawarman (1347–79) whose inscriptions state he was "always concentrated on Hevajra". A feature of Javanese Buddhism was the deification and worship of kings as Buddhas or Bodhisattvas. Important Buddhist deities included Prajnaparamita, Tara, Bhairava and Lokesvara.
The fall of Majapahit and the rise of Muslim states such as the Sultanate of Malacca saw the decline of Buddhism in the region. Many escaped to the island of Bali after the end of Majapahit rule fleeing persecution, where Buddhism was merged into Balinese Hinduism. This process of merging Buddhism and Hinduism predated the fall of the Majapahit however, and many textual sources from the later Hindu-Buddhist kingdom state that Hinduism and Buddhism are both two paths to the same reality and also equate the five Buddhas with five forms of Shiva. Likewise, some Majapahit temples depict both Buddhist and Shaiva elements.