Jaana

Jaana is one of the Companions of the Avatar. She is a native of Earth, and friend of Lord British. In Britannia Jaana is a Druid,

Originally, she lived in the forest town of Yew. In Ultima IV she gladly joined the future Avatar in his/her quest to find the Codex of Ultimate Wisdom.

In Ultima V she was declared an outlaw by Lord Blackthorn, and retreated to a secret location of tunnels deep under Yew, where she worked with the Resistance against the Dark Lord's rule. When the Avatar came, she gladly joined him/her on the quest to topple Blackthorn.

By Ultima VI, Jaana again lived in Yew, but the quiet life of a town druid wasn't really for her, and she was horribly bored. So when the Avatar came to Yew to search for the Rune of Justice, she gladly joined the party to assist in the quest of the False Prophet.

200 years after the gargoyle war in Ultima VII, Jaana had moved to the town of Cove, and worked there as a healer. She was in love with the town's mayor, Lord Heather. While the Ether was disturbed by the Guardian's Generators, it didn't quite have the same effect on her as it did to other magic-users of Britannia; she remained sane and was able to use magic normally, albeit with much exhaustion on her part. She joined the Avatar's party when he/she came to visit Cove.

In Ultima IX Jaana was seduced to service in the Wyrmguard, where she came under the control of the Guardian. The Avatar was able to free her, and she would later assist him in the final battle against his arch nemesis.

Real-life counterpart
She is based on a real-life friend of creator Richard Garriott. Her real-life counterpart, who holds the same name, is from Finland, where the name is indeed common. (However, it should be noted that in Finland, the name is pronounced [jɑ:nɑ], i.e. Finnish "J" is pronounced roughly like English "Y".)

Trivia

 * Her character portrait in Ultima VI is REALLY horrible. Thankfully the designers decided to give her a much younger and better appearance in Ultima VII.