Sir Terry Pratchett is a knight more than a man. We all know this. So, after he was knighted, he decided to make his own sword! He smelted his own ore, and infused a few meteorites he had lying around into the blade.
So, Sir Terry then decides to take the sword and tuck it away in a safe place so those pesky government fellows would not find it and use it to further destroy the good people of Earth and beyond. Thanks pal !