Although his work suffered frequent setbacks, Karl Benz was given strength by Bertha Benz's unshakeable belief in her husband and his invention. On 29 January 1886, he applied for a patent for his three-wheeled "vehicle with gas engine".
The success of the company, which shaped the future of personal mobility, can largely be attributed to Bertha Benz. Patent DRP 37435 is recognized today as the birth certificate of the automobile.
Karl Benz went on to build further, improved versions of his Patent Motor Car. Yet despite a generally enthusiastic reception from the public, the commercial success he craved remained elusive. Once again he became racked with self-doubt – and once again it was his wife who found a way out. She recognised that the general public remained suspicious of the practicality and reliability of this driving machine, which some people saw as powered by "mysterious forces", and came up with the idea of a publicity drive.