Isshin Kurosaki
According to his robe, he was a captain. Perhaps, Zero Division or before they was an "organized" Gotei 13.<-- (throwing the ball pretty far) Since, the original members of the Gotei 13 are Shinsoui, Ukitake, Unohana, and Yama-ji.
<- first chapter of the Turn Back the Pendulum -
Shinsoui stated "the original Gotei 13," the way it sounds Seireitei wasn't really that organized until commander-general Yamamoto took charge and change everything.
For the picture with Urahara announcing he is their new captain. Someone claim it was Isshin in the background, the short guy in the back row and barely able to see over the two guys shoulder. I have no clue for that. I look into it some more before I come up with a theory.
Zaraki Kenpachi was not a member at the time because Tousen Kaname "listen (couldn't witness it)" when Zaraki killed the previous 11th squard Kenpachi to order obtain the Captain seat. Zaraki is out the picture for being the Captain. -
www.onemanga.com/bleach/146/02 -
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His carrying his zanpaktou which a higher ranking officer or a daimyo would carried his during the feudal ages. It's called Ito Maki Tachi.
http://www.geocities.com/alchemyst/glossary.htm
And, I do not believe Isshin is, Kaien, Kuukaku, and Ganju, father. Another curve ball, the hilts of Kaien and Isshin are different. Ichigo regular zanpaktou had the strings attach to it, same as Isshin. After Ichigo release Zangetsu in his shiki and bankai, something is still something attach to the hilt.
I'm not saying Isshin would have something similar to it. I think KT is playing with us.