The Galactic Empire

Summary
The Galactic Empire was formed in the year 9 BBY by Chancellor Ducau Zaoku, after the suicide of previous Chancellor Tamara Karsguard. The Inner Council is renamed the Imperial Council, and the Galactic Senate now the Imperial Senate. The first Emperor of the Empire was Ducau Zaoku.

Supreme Head of State and Government
The Emperor is the highest executive position and highest ranking power within the Galactic Empire. The Emperor doesn't need any approval from the Imperial Council, Senate, or Supreme Court. The purpose of having this position was to bypass the constant gridlock within the Senate that nearly destroyed the Republic before, during, and after the Clone Wars. Ducau Zaoku was the first Emperor of the Galactic Empire, at the age of 76 when he first created it.

The Emperor's second in command is the Grand Vizier, who took the place of the previous Vice Chair from the Old Republic. The Grand Vizier oversees sessions of the Senate and solves humanitarian issues within the Empire, whereas the Imperial Council and Emperor handle the bulk of the real problems. The first Grand Vizier to Emperor Zaoku was Padme Amidala-Skywalker.

Imperial Council
When the Empire was first formed from the crumbling Republic, the Inner Council was just renamed as the Imperial Council. All members maintained their positions as representatives from their galactic regions, however; the Councillor of the Core was eliminated for the Emperor assumed that position. The others, Darkan Gollak of Neimoidia, Kovo Karacta of Kintan, Khen Su of Kamino, Selena Vataris of Onderon, Naveeneo Kariin of Iktotch, still kept their positions. The Imperial Council was not the sole commanding force of the Imperial Military, but became second in command to the Emperor regarding the military. In a sense, the Imperial Council and Grand Vizier have equal power and must work together in the case that the Emperor could not serve.

The Imperial Council grew larger in the year 3 BBY, increasing in size from 5 members to 7. The new members are the current Grand Admiral (Amelia Daala) and the current Chief Justice of the Supreme Court (Arlo Pontaco).

Imperial Senate
The Imperial Senate lost most of its power in 9 BBY when the Republic was reorganized into the Empire, and now its sole duty is to discuss and solve humanitarian issues around the Galaxy. The Imperial Senate is governed by the Grand Vizier and (new) Vice Chair. The Vice Chair of the Empire is different from the Republic, where now the office's sole duties is to assist the Grand Vizier when holding and running sessions of the Senate. If the Grand Vizier can't attend a session of the Senate, the Vice Chair substitutes in for the time being.

In order to get humanitarian resolutions passed, like sending aid to star systems, the Senate can vote in favor to pass it or not. The Grand Vizier must approve of the resolution, but that doesn't mean it gets done. The resolution can now move forward to the Emperor, who has the final say in whether it should be passed or not. In some degree, the Grand Vizier has an extremely heightened power in the Senate, having capabilities to block literally any piece of legislation or resolution; preventing from the Emperor even seeing it. That means that a corrupt Grand Vizier could cause much trouble in the Empire, so; the Emperor had to make sure he chose the right person to serve alongside him... Padme Amidala-Skywalker.

Imperial Supreme Court
The Supreme Court didn't change much in the Empire, besides the fact that it can't amend or change any law without the approval from the Emperor.