Martingo, from Ultima VII
Martingo is the self-proclaimed "Sultan of Spektran", ruler of the isle of Spektran in Ultima VII. But in reality he is just a rich man who has lost his mind. Still, he has the best guarded treasure chamber of all in Britannia. The Book of Fellowship claims that Martingo hates visitors.
The Avatar had to meet him when Lord Draxinusom said that he had been forced by circumstances to sell his Ether Ring to him some years ago. Martingo was totally uninformative when talking to him, babbling mostly delusional gibberish. However, he informed the Avatar that he'd be willing to give up the ring if the hero managed to get it from his secure vault. It was a trap, as the ring was guarded by a Stone Harpy. Defeating the harpy and retrieving the Ether Ring, the Avatar left Martingo alone with his madness and delusions.
- Martingo's madness shows itself, beside others things, by talking to non-existent people, having a imaginary harem and believing himself an important ruler.