Once again Detlef, on the money!
The Iranun originated on Mindanao like Detlef said, but many traveled (or pirated), some to North Borneo (Sabah region for example) and other places like other Moros. They like the Maranao and the Maguindano, they favor the kampilan.
You can learn more here:
https://en.wikipedia.org/wiki/Iranun_people