After completing the training, Drona gathered all his disciples around him. He then set a task for them to accomplish. It was customary for the disciples to offer a Gurudakshina, or payment to the teacher for the lessons. This could be in kind or as service to the teacher as demanded by him.
Drona wanted their service to fight and defeat Drupada, the king of Panchala, and bring him to Drona. All including the teacher, himself, knew that it was a hard task. Drupada and Drona were both trained by Parasurama and had acquired matchless skills from him.
Duryodhana took it as a challenge and an opportunity to impress all including the teacher. He went with a large army in the company of Dussasana and his other brothers and Karna. They surrounded the palace of Drupada and challenged him. Drupada came out with a huge army with able support from his brother Sathyajit. After a fierce battle the Kaurava army was crushed. Duryodhana and his supporters came back in disgrace.
Arjuna anticipated this. He had told Drona when he saw Duryodhana rushing to Panchala that he would accomplish the task after the Kauravas returned. Accordingly, he started in the company of Bheemasena leading an army to face Drupada. He spared his other brothers from the task. Bheema crushed the defending army of Drupada with his fearsome club. Arjuna was there just behind sending showers with his sharp arrows. Sathyajit had to flee the battle field, unable to face the onslaught. After a fierce battle Drupada was defeated by Arjuna and bound as a slave. Arjuna then brought him as his gift to his teacher.
Drona was delighted. What was the condition of Drupada? He lost not only his kingdom and all wealth, but, even his life was at the mercy of Drona. The two would have found their earlier roles reversed. Drona had no intention of hurting Drupada. Instead, he immediately released him from bondage and seated him next to himself. Then he addressed the defeated king of Panchala with kind words.
Drona said that, as a Brahmin, he did not covet any wealth or power. Instead, he cherished the friendship of his comrade of student days. Since Drupada would entertain friendship only with equals Drona had to take this approach. Actually, the entire kingdom of the Panchalas, won in battle by his students, thus belonged to Drona. But, that was not his intention. He would retain only half of it and return the other half to Drupada. Thus he would become equal to Drupada and qualify for his friendship ! The kingdom of the Panchalas south of the river Ganga would belong to Drona. The other half to the north would remain with Drupada . So saying, Drona sent Drupada back to his palace .
Drupada felt humiliated. At the same time he was also highly impressed by the valour of Arjuna. He wanted to take revenge on Drona for this humiliation and win friendship with the Pandava . We shall see later how Drupada found a way to achieve both these objectives. .