Star Wars F A O Mozz....

[ToraToraTora]

In EP 4 The character is "Governor Tarkin" - later in the star wars world he is known a "Grand Moff Tarkin" - why is that?

[DDIL]

this could explain it better than I can
 

Governor

Tarkin was elected as the governor of his home planet before the Empire was formed. He served the Galactic Republic's Judicial Department before returning to his home planet. 

Grand Moff

Tarkin became the first Grand Moff after Darth Sidious transformed the Republic into the Empire. He was promoted to Grand Moff after leading pacification efforts against Separatist forces during the Clone Wars. 

 

[ToraToraTora]

ah I see, so he was both! cheers.

[DDIL]

I was typing a response and it got into it way to much so found and simplified explanation on the net. Glad it helped 

[ToraToraTora]

So EP4 was set after the clone wars so when Leia addresses him as Governor on the death star is she mocking or has she not heard about his promotion?

[DDIL]

Yes it's after the clone wars.

I don't know if she's mocking him or his rank

[ToraToraTora]

...or she's just not aware?

[DDIL]

I don't know I never really thought about it

[ToraToraTora]

Mozz is our resident expert lets see what he says.

[chelle7272]

I dont think anyone ever calls him Grand Moff to his face, but I believe Leia is sassing him alongside her other comments - foul stench etc. 

[Mozz71]

As far as I know, the just represent different roles. He's the governer of his home planet of Eriadu (much like Papatine is of Naboo in the prequels), but his military rank within the Imperial navy is Grand Moff, second only in power to the Emperor.