Original: Despite its tiny territory, this was an autonomous duchy from 1680 to 1826; in 1684 the capital was moved from Heldburg to Hildburghausen, and the mini-state became known as Saxe-Hildburghausen.
Simplified: Although it was very small, Saxe-Hildburghausen was an independent duchy from 1680 to 1826. In 1684 the duchy changed its capital from Heldburg to Hildburghausen, and changed its name to Saxe-Hildburghausen.