The kingdom of Pan(n)ai: 11th century-14th century. Located in the prov. of North Sumatera.
The location of this kingdom is precisely in the valley of the river Panai and Barumun that flows in district Labuhanbatu and district South Tapanuli.
* Foto kingdoms on Sumatera: link
* Foto ancient sites on Sumatera: link
History of the kingdom
Because of the scarcity of inscriptions and historical records, this kingdom is among the mysterious and least known polity in Indonesian history. Historian suggested that the Pannai kingdom was probably a principality or a vassal allied under the Srivijayan mandala and later to Dharmasraya kingdom. The historical records mentioning this kingdom can be found from Indian and Javanese sources.
Despite the lack of local historical records, on the upstream of these rivers however, 16 Buddhist Vajrayana temples were discovered. These temples today are known as Padanglawas temple compounds, one of them are Bahal temple. Experts suggest that the existence of the temples is related to the Kingdom of Pannai. The temples is the traces of Vajranaya Buddhism in Sumatra. The place is most probably a religious-complex for warrior-monks of and had a key role, being located mid-way in the Strait of Malacca in policing the trade within the area and repelling invading forces as well as providing spiritual guidance to any pilgrim from China, India or within the archipelago.
The state of Pannai, according to inscriptions found in India, fell after a surprise attack from the rear. Pannai did not suspect an attack from a Chola occupied Srivijaya, the mandala’s capital.
Source (english)
– History Pannai: Wiki
Source (indon. language)
– Sejarah kerajaan Pannai di Wiki: Wiki
– Sejarah kerajaan Pannai: http://www.bimbie.com/sejarah-kerajaan-pannai.htm
– Sejarah kerajaan Pannai: http://trendmagtheme.blogspot.co.id/2012/10/kerajaan-panai-pane_21.html
Foto

The Center of the Batak Kings was in Pannai, (Pananiu or Panaiu) which, is thought to exist in Padang Lawas. And in this area there is found a temple complex built by around 11th century. The temple is estimated to be built Rajendra Cola I era.