The first of all Hokages; Senju Hashirama was the founder of the Hidden Leaf Village. He made his appearance in the story when Orochimaru summoned him in the fight against Sandaime Hokage, when he was launching the attack to destroy the Hidden Leaf Village with the Hidden Sand ninjas as allies. The First Hokage had a unique exquisite type of chakra element, the Hidden Wood element, which is a mix of water and earth-type chakra. Wood Release is his most famous jutsu, which enabled him to convert chakra into source of life; basically creating and manipulating trees at will. With it he was also able to bend the giant demons known as Tailed Beasts to his will.
The man known as the god of Shinobi, Senju Hashirama is perhaps the strongest man alive.