Sir Arbuthnot

Sir Arbuthnot is the former royal coinmaker, who'd fled to the lighthouse of Greyhaven in Ultima V.

Some time prior to Ultima V, Shamino and Dupre secretly ordered him to make the Codex Coin in order to summon the Avatar back to Britannia. He did as told, but the regime got word of it and he was put on the wanted list, being forced to flee to Greyhaven for safety. Sir Arbuthnot then had a suspicion and asked the Avatar about the current regime. The Avatar replied being against it, and when Sir Arbuthnot further asked about the true Avatar, the hero revealed the truth to him. Sir Arbuthnot felt honored that his hard work had paid off in the end.

Ultima V: Lazarus
In Ultima V: Lazarus, Sir Arbuthnot first only admitted that he was a former knight of the Order of the Silver Serpent of Serpent's Hold and the retired royal coinmaker. He was uncertain of why the silver serpent stood for his order, only knowing the same symbol had graced Lord British's Amulet. He was involved with Kenneth in a supply chain to Serpent's Hold, which was under a blockade of the Oppression.

After being shown the Codex Coin as proof of the Avatar's identity, Sir Arbuthnot shared the entire story of how he had been commissioned to create the magical artifact which summoned the Avatar to Britannia. The knight told the hero that an unknown member of the Resistance had tasked him with creating the magic coin, which he had been able to create using knowledge he had gleaned from his grandfather Azure, who had carved magic Runes during the time of Ultima IV. His access to the Royal Mint gave him cover for his activities. The difficult part had been devising the magic to send the coin to Earth, and while researching this he had alerted Blackthorn to his plans and had been forced to flee. He eventually met a mage that convinced him if he completed his task and gave the Codex coin to those who had commissioned him, Iolo and Shamino, the coin would eventually reach its desired location. It was shortly after that that members of the Oppression began searching Britain for him, and he was forced to flee to Greyhaven.

Trivia

 * Sir Arbuthnot is based on Bill Jensen (a.k.a. Arbuthnot Dragon). He was put into Ultima V after minting a coin with the codex symbol on one side and the Bell of Courage, Book of Truth and Candle of Love on the other and presenting it to Richard Garriott.