The Leader of Konoha, the hidden leaf village
So far 5 shinobi have gained the title of Hokage.
After gaining this position, the Hokage has their face carved into the mountain that shadows Konoha.
Hashirama Senju was the founder of Konoha, the Hidden Leaf Village. He is a memeber of the Senju clan and the older brother of Tobirama Senju (the 2nd Hokage), and grandfather of Tsunade (5th Hokage).
The 1st is known for his extremely rare Wood Chakra, which combines Earth and Water Chakra.
2nd Hokage - Tobirama Senju
Tobirama Senju is the younger brother of the 1st Hokage, Hashirama Senju. He is Tsundae's Granduncle. He is also a member of the Senju Clan. He is the former leader of Team Tobirama and a master in Water Chakra.
3rd Hokage - Hiruzen Sarutobi
Hiruzen Sarutobi is the Father of Asuma Sarutobi and the Grandfather of Konohamaru Sarutobi.
He uses Fire and Earth Chakra. Hiruzen can also summon Enma, the Monkey King who can turn himself into a staff which can alter its length and width (much like Goku's Power Pole).
He has probably the most powerful shinobi in history, and has been called the most powerful Hokage ever.
Earlier in his life he retired his title to Minato Namikaze the 4th Hokage, but since Minato died in the sealing of the Kyuubi, he had to take back his job. But ultimetly fell to Orochimaru when he sealed him away
4th Hokage - Minato Namikaze
Minato Namikaze is the Father of Naruto and died sealing the Kyuubi inside him to save the village.
Minato was tought by Jiraiya and was the teacher of Kakashi Hatake, Rin and Obito Uchiha.
Minato is the inventor of the incomplete Rasengan, the only person who could fully control Gamabunta and a master of Lightning Chakra.
5th Hokage - Tsundae
Tsunade AKA Princess Tsunade is the Great Grandaughter of the 1st Hokage.
Tsundae is one of the Legendary 3 Sannin, and was tought by the 3rd Hokage.
She is a master of Medical Ninjutsu, has amazing inhuman physical strength and can summon Katsuyu a giant slug.
She became Hokage because of Orochimaru's plan's to destroy Konoha.
6th Hokage - Danzo
Danzo is very militaristic and logical, believing that emotion is destructive. Following Tsunade's coma, Danzo was selected as the new Hokage. He was originally Hiruzen's rival for the position of third Hokage, and created a sub division of the Anbu called "Root." He allowed himself to be the subject of experimentation in order to become more powerful.