Mpu Gandring was a famous maker of kris, a type of Javanese knife. He lived during the Kediri era and was killed by Ken Arok, who had commissioned a kris from Mpu. Impatient, Ken used the unfinished kris to murder Mpu. Mpu then cursed the kris: it would be destined to kill seven generations of Ken Arok's family, including his own life.
References
Mpu Gandring Wikipedia(Text) CC BY-SA