The town and stately seat of Braunfels were first mentioned in 1246. Braunfels has had town rights since 1607. In 1950 Braunfels had a population of 3,337. In the course of municipal reforms, the aforesaid constituent communities, formerly all independent villages, were amalgamated with Braunfels in 1972.

Bonbaden had its first documented mention in 772, and so celebrated 1200 years of existence in 1972. Bonbaden is therefore one of Lahn-Dill's oldest inhabited places.

Schloss Braunfels, a stately home that had been built from a castle built in the 13th century by the Counts of Nassau, served as of about 1260 as the Solms-Braunfels noble family's residential castle. After Solms Castle had been destroyed by the Rhenish League of Towns in 1384, Braunfels Castle became the seat of the Counts of Solms. Over the castle's more than 750-year-long history, building work was done many times. Particularly worthy of mention is the town and castle fire of 1679, which burnt much of Braunfels and its stately seat down. Both were then built into a Baroque residence. Schloss Braunfels was rebuilt out of materials that were still on hand. The town was given a regular marketplace, which is still preserved today and lies before the town wall.