A, the First Raikage, was the First Raikage of Kumogakure in the Land of Lightning and the founder of Kumogakure. He was one of the Five Great Kage who brought peace to the chaotic era and had participated in the First Five Kage Summit in shinobi history. He was the founding patriarch of Kumogakure in the Land of Lightning—the First Raikage.
During the early days of the nation's founding, A established Kumogakure of the Land of Lightning atop towering mountain peaks with his immense strength, becoming the Raikage.
Five Kage Summit: After the Five Great Nations had been initially established, the First Raikage, A, was invited by Hashirama, the First, to attend the unprecedented First Five Kage Summit alongside the other four Kage in order to discuss the distribution of the Tailed Beasts. During this time, the Second Raikage, A, served as his guard. At the meeting, Hashirama, the First, accepted his younger brother Tobirama Senju's suggestion to exchange the Tailed Beasts for money and divided the nine Tailed Beasts equally among the Five Great Nations. Thus, the Five Kage concluded the shinobi world's first peace treaty, bringing comprehensive peace to this land for the first time. Yet this peace had an expiration date: Hashirama's lifespan. Once Hashirama died, the nations no longer had anything restraining them, and the First Shinobi World War broke out.
Fourth Shinobi World War: During the Fourth Shinobi World War, he was summoned from the Pure Land into the shinobi world by the Sage of Six Paths' chakra, appearing in soul form. After Kaguya Otsutsuki was sealed, he joined the Sage of Six Paths' chakra and the other sixteen deceased Kage in using the "Summoning Technique" to transfer Team 7, the nine Tailed Beasts, and the critically wounded Uchiha Madara from the Beginning Ball Dimension