Third Shinobi War
This war took place 10 years before the start of the Naruto series. When the supremacy of the Five Great Nations began to weaken, numerous revolts broke out and this spread of violence started a war between various villages and countries. This war ended when Minato Namikaze was able to defeat a Thousand Shinobi of Iwagakure on his own, and Ōnoki who was reluctant to accept the peace treaty and all other nations were then forced to accept the peace treaty.
These heroics led Minato Namikaze to become the fourth Hokage of Konohagakure. This war saw the death of Third Raikage, and the rise if fourth Hokage. Again, this war lasted for a couple of years. Obito Uchiha died during this very war. Along him with him, It was during this war when Rin sacrificed himself, when she was forcefully turned into a Jinchuuriki. Just to save Konohagakure she used Kakash’s Chidori to kill herself. This was witnessed by Obito Uchiha who then started follow Madara Uchiha’s plans, which later bought the fourth great war. Sasori made name as ‘Sasori of the Red Sand’ during this war, and left Sunagakure later.