Tenno Jimmu

Tenno Jimmu was the first Tenno of the Genji Empire and the direct ancestor of all Tenno after him. The Tenno's bloodline, or the House of Genji claims it's right to rule the Sub-sector through him as the ancestor of all Tenno.

His detailed account is given in the Genjijiki, a chronicle of the Genji clan only to be read exclusively by the Tennos and their immediate heirs.

Early life and the Great Crusade
According to the beliefs of the Imperial shrines of the Genji Sub-sector, Jimmu is believed to have been a descendant of Holy blood. It is known that he was born on 13th February of an unknown year as the youngest out of the four brothers that were the sons of a king that ruled Takakicho, a city on a world called Yamato. His heritage before is only written in earlier texts and if true, he is a descendant of a group of beings called "Kami" that lived in the Sub-sector and were worshipped as Gods.

As Jimmu came to the age of 45, he had a dream of an three-legged raven sent from Holy Terra who told him of his destiny to unite the Sub-sector under the banner of the Emperor of Mankind. He gathered his brothers and told them his vision of uniting the Sub-sector. They departed their city with their armies and gatherered followers from other cities and cities to join their cause and sparked a mass migration. Jimmu's older brother Itsuse led the migration and moved East towards Kashihara, the Planetary capital of Yamato. When they reached Naniwa, they encountered a warlord called Nagasunehiko and Itsuse was killed in their first battle. Jimmu realised that they lost because they fought Eastward, against the direction of Terra. He chose to leave the city, established a stronghold in Mie, fought the Shogun at Nara,facing West towards Terra at the time and emerged as the victor. With the victory Jimmu has crowned himself the Tenno, the ruler of the Sub-sector chosen by the Heavens at the age of 51.

Post Horus Heresy
Tenno Jimmu designed the seal of the Tenno. He believed that the galaxy was divided into six corners and Humanity in the centre. He came with the term "Six chords under one roof" and the roof spans from Holy Terra to the rest of the Galaxy. All of Humanity is under one roof that spans in six directions with the foundation coming from Holy Terra.

Finding a wife
Now aged 52, but youthful as a descendant of the Kami Jimmu traveled to find a second wife. He fell in love with Isukeyori-hime, another descendant of the Kami like him. Sending Okume to speak to her on his behalf at first, he later sang his proposal to her. He had two children with her, Suizei becoming his successor.

Death
"My mission set by the Heavens to unite the Sub-sector is complete. I can die without despair in my mind to weigh me. I have faith my sons and sons yet to come to guide the Sub-sector under the Light of Holy Terra after my soul leaves for the Warp. The Emperor protects those of the Faithful, living or dead." - Jimmu's writing found after he passed away

Tenno Jimmu died at the age of 127 from old age, a fate only deserved by the virtuous. He died with his mission of unity complete. He is venerated at the Unebi-yama Shrine in Nara and only his successors can enter the shrine. His name standed for "Divine Might". His son with Isukeyori-hime, Suizei became the second recognised Tenno shortly after his death.

Legacy
Tenno Jimmu left behind a large mark on the Sub-sector. He has managed to unite all under his banner with his crusade. His descendants took the role of the Tenno from him, carrying on to rule the Sub-sector. The seal he designed became the symbol of the Sub-sector and his philosophy of the unification of Humanity under Terra's roof. His saga is preserved by the local Priesthood and recited on the Foundation Day.

Jimmu was bestowed the honour of a Saint by the Ecclesiarchy (despite their dismissal of him as a Pagan prophet) and as a result became the patron saint of the Sub-sector, revered by all of the faithful.

His direct surviving descendants include Sugihito, the current Tenno, Jingu Genji a High Lord of Terra and Alexander Macallan a disavowed member of the bloodline. From the alternate timeline, he is survived by Tydridalamor, Veliselyne, Erisvia and Werner Karius.

The Tenno has a tank named after him, widely used by the forces of his descendants. A second tank design was named after him later on.

The ten-thousandth year of Tenno Jimmu's unification was celebrated on 016.M42, observed by Sugihito.

Pagan Saint
Tenno Jimmu is not accepted as the prophet of the Emperor as the Ecclesiarchy. The Genji Cult was was forced to reform their scriptures to remove his ancestral linage from the Kami. His sainthood is barely accepted by the Ecclesiarchy in return, giving some legitimacy to the Genji dynasty.

Wargear
The founding Tenno, originally hailing from a Feudal World and to fight Yoshiemon has incorporated weaponry and armour with varying technologies. Of note are the following:

Magatama
The Magatama are comma-shaped beads, seven of them attached to a gold necklace. It was worn by the ancient Tenno until his death and it is now secured by priests.

Hagane Carapace Armour
The Carapace Armour was one of the gifts from the Adeptus Mechanicus as a sign of their alliance. The armour was designed with Miyagi's homeworld in mind, resembling the armour of samurais. Blessing have been made on the armour to maximise possible protection.

The armour is currently stored in the Tenno's residence.

Kusanagi blade
The Kusanagi blade is a sword that belonged to Jimmu's ancestors. The sword is said to be able to cut through thick armour with ease thanks to being blessed by Holy wards. The Tenno used the sword in battles in his lifetime.

The sword survives to this day and is only seen by public eye during Tenno's Accession ceremonies privately held by Imperial priests. Close examination of the sword is unavailable and not allowed for being considered the Regalia of the Tenno. The current location of the sword is unclear but is tightly protected by priests.

Composite bow
The longbow is the only weapon Jimmu was unwilling to trade for superior projectiles. He mastered archery to the point that he can search for an exposed region of armours to do proper damage.

Currently the longbow is stored in the Tenno's residence, never used for nearly ten thousand years.