The titles that result from the Chancellery building are named differently according to faction.

Chancellery:
Almohads - Grand Vizier
Byzantines - Chancellor of the Palace
Egyptians - Grand Vizier of the Palace
French - Chancellor
Italians - Chancellor of the Major Council
English - Chancellor of the Exchequer
Germans - Imperial Chancellor
Polish - High Chancellor of Poland
Spanish - Keeper of the Privy Seal
Danes - Chancellor of Denmark
Turkish - Grand Vizier
Russians - Chancellor of All The Russias

You bestow this title on your general, I think you can check a box to do this automatically, the same as bestowing the governorship of provinces.

Maybe after the building for this title was built,and the title was bestowed on a general, it got destroyed in a battle for the province, an earthquake or flood? That would be my guess.