Yuyudhana (Sanskrit: युयुधान, Yuyudhāna), better known as Satyaki (Sanskrit: सात्यकि, Sātyaki), was a powerful warrior belonging to the Vrishni clan of the Yadavas, to which Krishna also belonged. According to the Puranas, he was grandson of Shini of the Vrishni clan, and son of Satyaka. A valiant warrior, Satyaki was devoted to Krishna and was a student of Arjuna.
Satyaki strongly and passionately favored the cause of the Pandavas over the Kauravas in the Kurukshetra War, despite the fact that the Vrishini army had been promised to Duryodhana by Krishna. Satyaki accompanied Krishna to the Kuru capital, with Krishna as the emissary of peace which was ridiculed and turned down by Duryodhana.
During the war, Satyaki is the commander of one akshauhini of the Pandava army.
The fourteenth day of the conflict features Satyaki in a prominent role. With Arjuna attempting to pierce Drona's formation, in order to fulfill his oath of killing Jayadratha, Satyaki defends Yudhishthira from Drona, who was attempting to capture the emperor in Arjuna's absence. Rescuing Dhristadyumna from Drona, Satyaki engages in a long fight with Drona, taking up the morning's fight. Drona gets so frustrated by Satyaki, that he even uses divine weapons, which Satyaki counters using his knowledge of divine weapons from his education under Arjuna. Eventually, Satyaki tires, and he is wounded by Drona's arrows. He is rescued by a new attack from the Upapandavas. Ultimately, Satyaki manages to stall Drona long enough that Duryodhana, frustrated with Drona's lack of progress, withdraws Drona to focus on the conflict with Arjuna.