Founder of the noble Rust dynasty, Rust was made a Baron by the king of Ankh-Morpork for his great feat of arms in battle.
It all goes to show that all 'noble' lines must start somewhere, often away from peole who dress well and know which fork to eat quails eggs with. Instead the founder is normally some warrior who has impressed the king of the day by making mincemeat of the king's foes.
Rust's deeds are very reminiscent, of the fictional King Richard IV of England who appeared in the BBC comedy series The Black Adder (series1), played by Brian Blessed. In the episode Born to Be King, Richard IV was last seen entering Constantinople alone, armed with only a fruit knife and facing 10,000 Turks armed with scimitars, seemingly clearing the way for his son Edmund to become king. However he emerges victorius and returns to court praising 'my trust potato knife'.