Gira was Jedi Knight, one of the last to die in the Jedi Purge. Darth Vader had been hunting and killing Jedi for some time before he eventually came for Gira. With Gira was the last of the Padawans of the Jedi Order, a group who Gira had decided to give his life to protect. In a remote location, in a base where the Padawans could be kept safe, Darth Vader soon found them and sent in squad after squad of stormtroopers to eliminate the Jedi threat.
However, Gira fought courageously, fought harder than perhaps he had fought in his entire life. Gira, one man, held back dozens of stormtroopers, willing to sacrifice himself if it meant giving his Padawans a chance to escape. Soon however, Darth Vader himself came to confront Gira when there were no more stormtroopers to send before him. However, Gira met Vader face to face, throwing everything he had at Vader. Unfortunately, Vader was just too powerful. Gira was thrown about like a rag-doll and beat him down until Gira had nothing left to match Vader with.
However, instead of killing Gira, Vader offered him a compromise. If Gira would swear loyalty to Vader and join him and the Emperor, then the Padawans' lives would be spared. With some hesitation, Gira kept coming back to the fact that it was his duty to protect their lives, that they were the only thing that mattered, and although they would face Vader someday, that particular day, the Padawan's would survive. Accepting Vader's offer, Gira was relieved to know that the Padawan's would not die that day.