Troilus

Troilus was the sixteen-year-old son of King Priam of Troy and the younger brother of Hector, Paris and Cassandra. He killed the Greek warrior Achilles in revenge for the death of his brother Hector in circa 1200 BC.

After the Trojan War, he and fellow teenager Vicki Pallister, who had changed her name to Cressida, settled down with Troilus' cousin Aeneas, and went on with him in search of a new home. (TV: The Myth Makers)

At one point in their travels, they came across the Eighth Doctor, who was travelling with Charley Pollard and a young William Shakespeare. (PROSE: Apocrypha Bipedium)

Vicki had trouble to adjust to her new life, since nobody shared her memories or her values. The Trojans thought she was possessed or insane, and wanted to abandon her on a rock in the middle of the sea. However, Troilus stood by her, and eventually the couple left Aeneas and settled down in Carthage, while the others went on their journey. They had two sons, and apparently lived a happy life. (AUDIO: Frostfire)

Behind the scenes
In The Storyteller, a minisode released in conjunction with the announcement of Doctor Who: The Collection — Season 2 Blu-ray boxset, Vicki is seen talking to a young child, Sophia. While it is implied that they are related, it is not explicit.