Greymarch, from Ultima V: Lazarus
Greymarch is a fighter who had been captured by the Oppression.
The Avatar found him in the jail of Yew in Ultima V. He'd given up all hope, especially since he hadn't heard of his son Froed in a long time. However, when the Avatar told him that Froed was well in Skara Brae, Greymarch gained new hope and told the Avatar that the Sceptre of Lord British is very powerful and to consult Sir Simon in Bordermarch.
Ultima V: Lazarus
In the Lazarus version, his story is more detailed: Greymarch was born in Skara Brae, but went to live in the wildlands with his son. Eventually, they decided to go back to the cities. While in Trinsic, Greymarch tried to protect Anniel when she was attacked by a Shadowlord who wanted to take the sceptre she carried. He failed, however, and was taken prisoner by the Oppression because it was not permitted to attack a Shadowlord. His son was beaten by the guards, but he was able to flee the city with the help of a paladin. After witnessing the beating, Greymarch thought that Froed had died, and got depressed. When he hears the good new from the Avatar, he actually is animated to break out, in order to join his son. After freed, Greymarch and his son vanish, looking to hide from the Oppression.