Udyoga Parva is about the preparations for war between the Pandavas and the Kauravas, since the Kaurava king Duryodhana refused to give back the kingdom of the Pandava king Yudhishthira. The Pandavas had successfully completed the 12 year long exile into forest and 1 year incognito life as per their promise, in order to regain their kingdom lost to Duryodhana subsequent to their defeat in the game of dice. The Pandavas camped at the city of Upaplavya and summoned other kingdoms and kings for becoming their allies for the war. The Kauravas also did the same. Both of them amassed huge armies from various kingdoms of ancient India. However many people including Yudhishthira wanted to avoid a colossal war. War can destroy the whole economy of ancient India and can cause huge loss of human population. They sent messengers to Duryodhana to avoid war. Duryodhana rejected them all and send his own messenger who provoked the Pandavas and urged them for battle. As a last resort Vasudeva Krishna went for a peace mission from Upaplavya to Hastinapura, the capital city of the Kauravas. Krishna's mission also failed. Thus war became certain.
Krishna travels for his peace mission from the Matsaya city of Upaplavya to the Kuru city of Hastinapura, passing through many beautiful villages.