Commendations:

His first assignment was around 2250 as an Ensign aboard the U.S.S Republic. This brief tour was to cause a rift between him and his close friend, Ben Finney, when he recorded a mistake, in the ship's log, made by Finney. Finney blamed Kirk and the incident for his subsequent failure to ever gain command of a starship.
Kirk was still at Starfleet Academy when this incident occurred.

His first assignment, after graduating from the Academy, was on the U.S.S. Farragut. While serving aboard the Farragut., in 2257, 200 Farragut personnel (including Captain Garrovick) died at the hands of the Dikironium cloud creature on Tycho IV. Kirk felt he could have saved these lives if he had fired on the creature earlier.
He found out, years later, that nothing could have prevented the deaths.

James Kirk is probably most famous for the five year mission of the U.S.S. Enterprise from 2264 to 2269 serving as ships Captain.
It was during this tour, in 2267, that Kirk became the first starship captain ever to stand trial. The trial took place at Starbase 11 where Kirk was accused of causing the death of Ben Finney.
Kirk was found not guilty of any wrongdoing and was exonerated.

In 2270, Kirk accepted a promotion to admiral and became chief of Starfleet operations and recommended Will Dekker to replace him as captain of the Enterprise.
In 2271, Kirk accepted a reduction in rank, to captain, and once again commanded the Enterprise to meet the V'ger (Voyager) threat..

Kirk retired some time after this and became romantically involved with Antonia. He returned to Starfleet in 2284 and became a staff instructor with the rank of admiral at Starfleet Academy. But bored with ground duties, he returned to active duty in 2285 when Khan Noonien Singh hijacked the Starship Reliant and stole the Genesis Device. It was during this mission that Spock, perhaps his dearest friend, died.
After the mission, Kirk hi-jacked the Enterprise and returned to the Genesis planet to retrieve, and return Spock' body to his home planet of Vulcan. Here, Spock was brought back to life when his body and katra were reunited.
It was also during this incident that Kirk had to order the destruction of the Enterprise so that it did not fall into Klingon hands.

Kirk was charged with 9 violations of Starfleet regulations in connection with the revival of Spock in 2285. All but one charge, disobeying a superior officer, were dropped, but the Federation Council were so grateful to him for saving the Earth from an alien probe, that he was given the captaincy of the second starship Enterprise.

In 2293, both he and Dr. Leonard McCoy were wrongly accused and convicted for the death of Klingon chancellor Gorkon. During the trial, the bitterness and hatred that Kirk had for the Klingon empire came to light and was monumental in Kirk' conviction. His feeling towards the Klingons had come about after his son, David Marcus, was murdered by a Klingon officer who was after the secret of the Genesis device, in 2285. Nevertheless, Kirk was instrumental in the success of the Khitomer peace conference, saving it from further attacks.

Kirk's second retirement came about 3 months after the Khitomer Accords were signed.

At the launch of the Excelsior class Enterprise - B, in 2293, Kirk was on board as an honoured guest. But a freak accident occurred and it was believed that he had died as a result.
In actual fact, Kirk had been drawn into a temporal anomaly known as the 'Nexus' and remained there until he emerged at the request of fellow captain Jean-Luc Picard in 2371.

It was while working with Picard, saving the inhabitants of the Veridian system, that he died at the hands of a deranged El-Aurian scientist, Tolian Soran.

James T. Kirk is buried on a mountain top on planet Veridian III. He went boldly, where none had gone before.