The major river of the region was and is the Mahakam River.
Location of East Kalimantan/ East Borneo
Young Ibans, or Sea Dayaks people
Kutai Martadipura is a 4th-century Indianized kingdom located in the Kutai area, East Kalimantan.
It is one of the earliest ancient kingdom in Indonesian history.
Seven stone pillars, or yūpa (“sacrificial posts”), have been found in Kutai, Kaman Estuary, near the Mahakam River.
The style of the script has been dated to the last half the 4th century.
An ancient yūpa/ inscription of Mulawarman, king of Kutai
The first ruler mentioned is Kuḍungga, the “lord of men” (narendra), his son Aśwawarman, styled the “founder of the dynasty” (vaṇśa-kartṛ) and grandson of the first and son of the later, Mulavarman called the “lord of kings” (rājendra).
It was Mūlawarman who let these inscriptions be made.
While nothing of the military actions of his two predecessors is known, “Raja” Mūlawarman is stated to have conquered his neighbours in battle.
He is also said to have increased the land of Kutai by a local ritual called “asvaredjwa”.
This ritual required a horse released to his land.
The footsteps of the freely roaming horse were taken as evidence that this land belonged to Kutai.
Mulawarman was also known for his tribute of gold to his God.