The Bass Brewery /ˈbæs/ was founded in 1777 by William Bass in Burton-upon-Trent, England. The main brand was Bass Pale Ale, once the highest-selling beer in the UK. By 1877, Bass had become the largest brewery in the world, with an annual output of one million barrels. Its pale ale was exported throughout the British Empire, and the company's distinctive red triangle became the UK's first registered trademark.