Timeline

Unknown time ago(Before officials Flash-backs)
 (See lower (or click) for period between 90 and 1 years ago)


 * Exile of Isshin Kurosaki from the position of a Shinigami Captain.
 * Aizen allies himself with some Hollows.

Between 2000 and 200 years ago

 * Yamamoto founds the Shinigami Academy.
 * Formation of the Gotei 13 - it is unclear exactly when the Gotei 13 was founded and could possibly pre-date the foundation of the shinigami academy.
 * Jūshirō Ukitake, Shunsui Kyōraku are among the first students to graduate from the Academy.
 * Captains Yamamoto, Retsu Unohana, Jūshirō Ukitake, Shunsui Kyōraku and other unknown shinigami make up the first Generation of captains.
 * Aizen begins experimenting with hollowifcation.

Between 200 and 100 years ago

 * Aizen is promoted to vice-captain of 5th division so Shinji can watch over him
 * Soifon begins her family obligations to protect Yoruichi Shihōin.

Aprox. 100 years ago

 * Captain of 3rd division retires, possibly interred in the "Maggots Nest" - Rōjūrō Otoribashi promoted to 3rd division captain.
 * Captain of 11th division(Another Kenpachi) is recently replaced by the next Kenpachi. It's unclear if this is the current Kenpachi or not.
 * Captain of 10th division recently met with an "untimely demise".
 * Captain Hikifune of the 12th division has been promoted to the Royal Guard. Kisuke Urahara, 3rd seat of the 2nd division is promoted as 12th Division captain.
 * Kisuke Urahara founds the Shinigami Research Institute and frees Mayuri Kurotsuchi from the "Maggots Nest" to co-lead the Institute.
 * Shuhei Hisagi is saved by Kensei Muguruma thus inspiring him to join the Ninth Division, (and to get a tatoo of the #69 on his cheek.)
 * Gin Ichimaru kills the former 3rd seat of the Fifth Division and is appointed the new 3rd seat by Lieutenant Aizen

Aprox. 91 years ago

 * Mysterious disparitions in Soul Society
 * Hollowification of the 9 actually known Vizard
 * Exile of Kisuke Urahara, Tessai Tsukabishi, the 9 Vizard and probably of Yoruichi Shihōin.
 * Death of the 9th's division High-seated officers, except Kaname Tousen.

Between 90 and 1 years ago

 * Byakuya Kuchiki marries Hisana, Rukia's sister, who dies after a number of years.
 * Byakuya Kuchiki adopts Rukia into the Kuchiki clan as part of his oath to protect her.

Current day - Substitute Shinigami/Soul Society Arc

 * Ichigo Kurosaki, unknowing son of a powerful shinigami, takes shinigami powers from Rukia Kuchiki
 * Aizen, Gin, and Tosen defect from the Soul Society