Mace Windu is a fictional male Human in the Star Wars series. The character was portrayed on screen by Samuel L. Jackson. His allegiance / loyalty is to The Old Republic. Mace Windu is the leader of the Jedi Council who appears in all three prequel films and in the Clone Wars cartoon series. For most part, he never leaves the Council Chambers. Mace Windu does take part on the assault on the Separtists base on the Mars like planet of Geonosis at the end of 'Attack of the Clones'.
Mace Windu is the most senior member of the Jedi Council and nothing gets done without his say-so in consultation with others such as Yoda. After Anakin Skywalker is found, it is Mace Windu who has to be persuaded to allow the child to be entered into the training program which Mace allows.
Mace Windu is troubled along with Yoda about the amount of influence that Palpatine is having on the young padawan Anakin Skywalker. When Palpatine assigns Anakin as his representative on the Jedi Council, Mace Windu is troubled by it. Mace didn't overrule but he doesn't grant Anakin the role of Jedi Master which angers Anakin. Mace just instructs Anakin to sit and shut up which Anakin reluctantly does.
Mace Windu take part in the Battle of Geonosis, the first real battle between the Old Republic and the separatists. Mace Windu confronts Count Dooku who is the leader of the separatists at the stadium where Anakin Skywalker and Padme Amidala are to be fed to local wildlife. Mace Windu is forced to escape when Trade Federation droids appear and attack Mace. Mace stays during and helps in the fight against the droids and the Geonosians.
After being alerted to the fact that Vice Chancellor Palpatine is a Sith-Lord by Anakin Skywalker, Mace sets off alone to arrest Palpatine. Mace and Yoda both knew there was a Sith Lord somewhere pulling the strings but they didn't realise it was the Vice-Chancellor.
Mace and two other Jedi knights go to visit the chancellor to arrest him but the Vice Chancellor puts up a fight and manages to kill the Jedi Knights accompanying Mace with ease thereby setting up a duel between Mace and Chancellor Palpatine. Mace looks like he is going to win the fight between him and the Palpatine. With Mace almost certain to win, Palpatine unleashes electricity at Mace which is captured by Mace's lightsaber and causes the Vice Chancellors face to be disfigured.
Mace wants to kill Vice Chancellor as he's too powerful to be put on trial but Anakin wants the Vice-Chancellor to be put on trial saying it is the Jedi way. Palpatine is saved by Anakin Skywalker when the Vice Chancellor tells Anakin that he can save Padme which Anakin believes.
As we only see Mace Windu flying out of the window into the night air, Samuel L. Jackson is hoping to put a spin on the story to get invited back for a return. There is a possibility that Mace could well be Supreme Leader Snoke who commands the remnants of the Galactic Empire now called First Order.
The character is played to perfection by Samuel L. Jackson who got the job after George Lucas saw him on an interview with Chris Evans on TFI Friday chat show where he said it would be his wish to appear in the films. Sam is the most well known actor to appear in the star Wars films who was already famous. Harrison Ford was made famous by his role as Han Solo.