Yuyudhana (Sanskrit: युयुधान, IAST: Yuyudhāna), better known as Satyaki (Sanskrit: सात्यकि, IAST: Sātyaki), was a powerful Yadava chieftain of Narayani Sena, belonging to the Vrishni clan to which Krishna also belonged. According to the Puranas, he was the grandson of Shini of the Vrishni clan, and son of Satyaka, after whom he was named. A valiant warrior, Satyaki was devoted to Krishna and was a student of Arjuna.

Satyaki strongly and passionately favors the cause of the Pandavas over the Kauravas in the Kurukshetra War. Prior to the war, Satyaki accompanied Krishna to the Kuru capital, with Krishna as the Pandavas' emissary of peace. He is a witness to Duryodhana's attempt to arrest Krishna and Krishna's Vishwaroopa form, though he is not mentioned as one of the few persons not blinded by the apparation. After talks break down, Satyaki leads the Sivi and Vrishni army to the Pandava's camp. While Satyaki, along with others like Chekitana and Syenajita joins the Pandavas, Krishna promises his army to Duryodhana. Hence, Yadavas sworn directly to Dwarka like Kritvarma fight for the Kauravas, meaning Satyaki has to fight his kinsmen in the war. He provides 1 Akshauhini army to the Pandavas. According to Bhishma, he is capable of fighting 12 Atirathis alone.^{[citation needed]}

During the war, Satyaki is the commander of one akshauhini of the Pandava army.

On the 2nd day of the war, Satyaki fought with Shakuni. Shakuni gave him a fierce battle. But Satyaki defeated him.^{[citation needed]}

The fourteenth day of the battle 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.^{[citation needed]}

Later in the day, Yudhishthira gets worried for Arjuna's safety. Despite his protests that protecting the king is more important, Satyaki is ordered to find and aid Arjuna. At the entrance to the Padmavyuha, he meets Drona. Knowing that he cannot bypass the sage, he circumvents him, telling Drona that he must duplicate the actions of his guru (as Arjuna had declined to fight Drona at the start of the day).^{[citation needed]}

As Arjuna is being attacked from multiple sides, Satyaki appears to give aid. Satyaki fights an intense battle with archrival, Bhurisravas with whom he had a long-standing family feud, following from when Satyaki's grandfather defeated Bhurishrava's father. After a long and bloody battle, Satyaki, already exhausted from fighting Drona, begins to falter, and Bhurisravas pummels him and drags him across the battlefield. Raising his sword, Bhurisravas prepares to kill Satyaki, but he is rescued from death by Arjuna, who shoots an arrow severing Bhurisravas's arm. When criticized by Bhurisravas for interfering in the fight without warning. Bhurisravas lays out his weapons and sits down in meditation. Satyaki then emerges from his swoon and swiftly decapitates his enemy. He is condemned for this rash act, but Satyaki states that the moment Bhurisravas struck his semiconscious body, he had sworn that he would kill Bhurisravas. With the day's battle nearly over and Jayadratha still far away, the debate on the morality of Satyaki's actions is shelved.

When the battle on the fourteenth day continued into the night killed Bhurisravas's father Somadatta, later assisting Bhima slay Somadatta's father, Bahlika.^{[citation needed]}