Hokage

The are the leaders of Konoha. They are generally the strongest in the village, although ideology and renown plays a large part in their being chosen for the position.

Five shinobi have gained this title so far.

First Hokage
The was the founder of Konoha, the older brother of the Second, and the grandfather of Tsunade, the Fifth Hokage of Konoha. His surname is Senju, while his given name is unknown. Together with his brother, the Second Hokage, he trained the future Third Hokage: Sarutobi. The First was famous for his jutsu, which allowed him to convert chakra into lifeforce and grow trees with ninjutsu. In conjunction with a special crystal that reacts only to his chakra, he could use this ability to suppress the Tailed beasts chakra. He saw the people of Konoha as a part of his own family, and his legacy takes a firm root in the village.

He was originally the leader of the Senju clan of the Forest. At some point in the First's life he fought Kakuzu but the nature of this fight is unknown at this point. In his early years, he allied with Madara Uchiha, and the two of them founded Konoha. Later on, he came to disagree with Madara over the policies of the village. This conflict resulted in the battle with, and defeat of, Madara Uchiha at the Valley of the End.

Later it was revealed that Orochimaru had implanted the First Hokage's DNA into sixty test subjects in an attempt to gain access to his Mokuton techniques and ability to control bijuu, producing Tenzo (later given the code name Yamato). However, he lost track of the test subjects and didn't realize that one had survived.

He is later revived from the dead by Orochimaru using Impure World Resurrection to fight the Third Hokage during the Destruction of Konoha arc. His soul is eventually sealed into the stomach of the Death God, along with his brother and Orochimaru's arms.

Second Hokage
The is the younger brother to the First Hokage and Tsunade's great-uncle. As the brother of the First, the Second Hokage was a member of the Senju Clan of the forest. The First and Second together fostered Konohagakure into a growing village. He was also, along with his brother, the teacher of the Third Hokage. He was very proud of his superior combat ability and his excellence with water jutsus, which allowed him to, among other things, use a water wall at full strength without a water source.

He is later revived from the dead by Orochimaru using Impure World Resurrection to fight the Third Hokage during the Destruction of Konoha arc. His soul is eventually sealed into the stomach of the Death God, along with his brother and Orochimaru's arms.

The Second is also one of Konoha's founding fathers, along with his brother the First, and Madara Uchiha.