Hashirama Senju

was the. He hails from the Senju clan who together with the Uchiha clan established Konohagakure.

Background
Hashirama was originally the leader of the Senju clan. Under his leadership the Senju clan came to be regarded as one of the two most powerful clans in the world, rivalling the renowned battle-oriented Uchiha clan. Because of this, when someone hired the Senju clan, the opposing side would hire the Uchiha clan and vice-versa, causing frequent battles between the two. Eventually growing tired of the constant fighting, Hashirama and his clan approached the Uchiha and offered a truce with them. Allied with Madara and his clan, the two groups founded Konohagakure.

When deciding who should become the leader of Konoha, the villagers selected Hashirama over Madara for the title of First Hokage. Fearing that Hashirama would oppress the Uchiha, Madara left the village, and challenged Hashirama's rule. After an intense battle that included the Nine-Tailed Demon Fox, Hashirama defeated Madara; and Hashirama's wife Mito became the Nine-Tails' first jinchūriki by sealing it within herself. In the aftermath of their battle, Madara was believed to have been killed, and the Valley of the End was created. To commemorate the battle, two statues, of Madara and Hashirama, were carved into the earth surrounding the valley.

During his time as Hokage, Hashirama came into possession of a scroll filled with, among other skills, various kinjutsu, which he sealed away in order to keep the techniques within it a secret. He also defeated Kakuzu, who had been sent to assassinate him by Takigakure. At some point, Hashirama gained control of several tailed beasts. He spread these beasts to other, newly-formed villages in an attempt to maintain peace and equalise the powers between the nations, but it did not stop the outbreak of the First Shinobi World War. Thinking about the future of Konoha, he and his younger brother, Tobirama Senju, trained the young Hiruzen Sarutobi. Hashirama died shortly after the founding of Konoha in one of the many wars that were raging during this revolutionary era, but not before passing on the title of Hokage to Tobirama.

Personality
Hashirama was shown to be a very calm and collected person, as well as kind and caring, with a deep sense of loyalty, great charisma and negotiation skill. He saw the people of Konoha as a part of his own family, and his legacy took a firm root in the village. He was also shown to be a very wise and insightful man, as he passed on great teachings to Hiruzen. It was he who first believed that all Konoha shinobi should show true loyalty to each other, and that a Kage must be willing to put his life on the line for his village to set an example for all others. This belief of his is known as the "Will of Fire".

Appearance
Hashirama is shown with dark tan skin, brown eyes, and long black hair. In most cases, he is wearing a similar style to his brother and Madara Uchiha; dark red, metal plating armour of that era similar to what samurai wear, ninja sandals, as well as some type of headband on his forehead, whether that is Konoha's forehead protector, or simply a red headband. He has however been seen in both on separate occasions. On each side of the collars of the armour is the Senju clan symbol. While in the village, Hashirama wore either the official Hokage garb along with a headband or a light brown kimono shirt with mesh armour underneath it held closed with a red sash and navy blue pants.

Abilities
Hashirama Senju is considered by many as the most powerful shinobi of his time. He was greatly respected by every shinobi during his life, such that Tobi claimed Hashirama was the one person whom he respected the most as well as detested. His prowess and abilities were so great that he was able to not only fight on equal footing with Madara Uchiha despite his power of Eternal Mangekyō Sharingan and having the Nine-Tailed Demon Fox at his side, but even gained victory in the end and survived the battle.

He knew how to perform a great number of techniques and was otherwise knowledgeable of those he could not. During his battle against his former student Hiruzen, he showed considerable taijutsu skill, able pressure the Third Hokage with it. In the manga, he also showed great genjutsu prowess, using the Bringer-of-Darkness Technique that covered the area in darkness which even Hiruzen couldn't dispel.

Nature Transformation
He was most famous for his unique Wood Release techniques, a kekkei genkai that is a mixture of earth and water-natured chakra that creates this new element. By converting chakra into the source of life, he was able to create trees, causing them to grow to great sizes and manipulate them to diverse shapes and battle uses at will. It was said that this ability was used to create the very landscape and foundation that Konoha is built upon. This ability appeared to be exclusively his, as no other known member of his clan has ever displayed its use. Even those who obtained this power through unorthodox means, such as Yamato, found his use of Wood Release to be much weaker in raw power.

The ability Orochimaru coveted him for was his unique ability to control tailed beasts. Of all his considerable talents, it was this ability in particular that made Hashirama unparalleled in the shinobi world, so much so that he is regarded as one of the few people capable of completely controlling a tailed beast. At one time, he had many of the beasts in his possession. This ability was greatly amplified by his crystal necklace, which Yamato suggested that he required to control even Naruto's partial lapses into tailed forms.

Invasion of Konoha Arc
Both he and Tobirama were revived from the dead by Orochimaru using Impure World Resurrection to fight Hiruzen during the invasion. While fully aware of what was going on, and saddened that he would have to fight his former student, Hashirama and his brother were robbed of their free will as a result of a seal employed by Orochimaru into the backs of their heads. Hiruzen quickly resolved to kill his masters and used a very powerful fire technique that was easily countered by one of Tobirama's walls of water that was then turned into an attack that was stopped by Hiruzen's own earth wall.

During the battle, he demonstrated great teamwork and combination attacks with his brother. He also demonstrated his great Wood Release abilities, forcing Hiruzen to summon Enma for assistance, and at the same time showed great taijutsu skills. His soul, along with his brother's, was eventually sealed by Hiruzen when he combined the Dead Demon Consuming Seal and the Shadow Clone Technique to strike both of them at the same time. Before his soul was completely removed, he and his brother apologised to their former student for the trouble they had caused.

Legacy
Because of the legacy of the Senju who are said to be direct descendants of the Sage of the Six Paths and the kekkei genkai that Hashirama possessed, it left his DNA highly coveted. During the battle at the Valley of the End where Madara Uchiha was thought to have died, the latter took the opportunity to collect his DNA, integrate it into his body, and allow him access to the Wood Release kekkei genkai. Some time after Hashirama's death, Orochimaru experimented with Hashirama's DNA. Desiring Hashirama's unique abilities, Orochimaru exhumed the Hokage's body and infused sixty child test subjects with his DNA, hoping that one would prove able to use Wood Release. Only Yamato survived the process. Danzō Shimura's right arm had also been infused with Hashirama's DNA through a similar experiment with Orochimaru, in the hopes of controlling the powers of the Nine-Tails, as well as to increase his physical energy to maintain the ten Sharingan embedded on his right arm as well as use the technique Kotoamatsukami within a relatively short span of time compared to the decade it would've taken on its own. Those cells also allowed him to use Izanagi.

With some of the cells taken from Hashirama, Tobi had created the White Zetsu, though his Wood Release is not as powerful. Tobi also implanted Hashirama's cells into his own body which allowed him to use Izanagi. He also had the cells 'planted' at his headquarters from which grew a massive flowering tree which has a mindless clone of Hashirama coming out of its base. It also supports the Demonic Statue of the Outer Path, and, having gradually been fed amounts of the tailed beasts chakra, among its roots, seems to have helped produce a legion of 100,000 White Zetsu clones for Tobi's army against the Allied Shinobi Forces' numbers of about 80,000.

Part of the legacy that Hashirama has also left behind is known as the Will of Fire, a belief held by all the members of Konohagakure. Tobi frequently mentions or remembers Hashirama, his musing over his sworn enemy tends to range from both utter contempt to a begrudging respect and admiration. Tobi does admit that Hashirama was the only person whom he respected of the Senju clan. Tobi also claims that Naruto has inherited Hashirama's Will of Fire while Sasuke Uchiha has inherited the hatred of his clan.

Trivia

 * is a Japanese word referring to the space between two pillars. This might be a play on the word, as the Hokage is said to be the pillar that supports the village. '柱' is also the counter word for gods and buddhas.
 * His face on the Hokage Monument has a crack across the bridge of the nose similar to Iruka Umino's scar. However, in flashbacks, no such scar is visible.
 * The necklace, worn by Tsunade and later worn by Naruto, originally belonged to Hashirama.
 * In the English dub version of the anime, his Wood Release was called "Secret Earth Jutsu" rather than "Wood Style". This was corrected in Shippūden with Yamato.
 * Hashirama, along with Tobirama, Minato, and the Konoha symbol, had his face appear in the ending omake of Shippūden episode 129 within the fireworks.
 * According to the third Naruto databook:
 * His hobbies were bonsai and wood sculpting.
 * His favourite opponent was Madara Uchiha.
 * His favourite food was mushroom mixed soup.
 * His favourite phrases were  and . They refer to perfect beauty without any artificial elements.

Quotes

 * (To Hiruzen) "The fellow countrymen of the Konoha make up each part of my body… those of the village believe in me, and I believe in them. That's what it means to be Hokage!"
 * "Whenever you live, there will always be war."
 * (As quoted by Kakashi) "Those who stray from the path of justice have no courage, but under the wing of a strong leader, cowardice cannot survive."