Ken Arok (or Ken Angrok), Rajasa (died c. 1227), was the founder and first ruler of the Singhasari (also Singasari) Kingdom, an ancient Hindu–Buddhist kingdom in the East Java area of Indonesia. He was considered as the founder of Rajasa dynasty of both the Singosari (Singasari) and Majapahit line of monarchs. He came from humble origins but subsequently rose to be the most powerful ruler in Java. His life was coloured with adventures, treacheries, and tragedies.
According to the Pararaton (The Book of Kings), a folklore tale re-telling about Kings of Java but which starts only from and mostly emphasis on Ken Arok with the myths combined, Ken Arok was the son of a peasant Ken Endok, who was the wife of a Brahmin Gajahpura in the kingdom of Kediri. His family was just a poor peasant family on the bank of the Brantas River in East Java.
Baby Ken Arok was placed in the Brantas by his parents who hoped he would be found by a wealthier family and get a better life. However, Ken Arok was found by a thief called Lembong. His foster father later taught him all his criminal skills and young Ken Arok grew to be the most cunning thief in Kediri. Doing much mischief and crimes, he was known all the way to the capital. Many people were sent to catch him, but none were successful.
One day Ken Arok met with Mpu Lohgawe, an Indian rshi who patiently taught Ken Arok to abandon his sinful life and start a new life. Lohgawe considered Arok as the avatar of Vishnu. His effort was successful and later he managed to get Ken Arok to become an attendant of Tunggul Ametung, a powerful regional leader of the Tumapel area.
One day, Ken Arok accidentally saw Ken Dedes, a beautiful wife of Tunggul Ametung, when she was taking a bath. Legend says when the wind blew over her dress and revealed her legs, Ken Arok said that he saw a beautiful light shining. He later told this to his teacher, who stated that it was a sign that Ken Dedes would bear a royal dynasty and any man that took her as wife would be a King. Ken Arok, already infatuated by her beauty, became even more eager to take her, by any means—including killing Tunggul Ametung, if necessary. By this time, Ken Arok had actually had a wife, a woman named Ken Umang from his village, and left her pregnant..