He tried to avoid fighting the Greek hero Achilles, despite his father's urgings. One day he found TARDIS and had it brought into the city, protesting when his father wanted to burn it. He was kind to Vicki Pallister, believing that she wasn't a Greek spy.
When Paris was forced by his father to seek out Achilles, he did so reluctantly. Instead of Achilles, however, he encountered Steven Taylor, who was pretending to be a Greek soldier named Diomede. Steven offered to let Paris defeat him in battle, then Steven would be captured and taken back to Troy, where he would tell everyone how Paris defeated him in battle.
Paris found what he believed was the "Great Horse of Asia" and had it brought into the city. However, it was full of Greek soldiers, who attacked Troy in the night. Paris was killed in the fall of Troy in circa 1200 BC. (TV: The Myth Makers)