In the late ’80 & early ’90s, British Knights (or “BK”, if you’re hip) were one of many trendy athletic shoe companies. While L.A. Gear focused on the sunny California lifestyle, British Knights went after the hip hop community and used then-mega rap star MC Hammer to help give the brand some street cred (yes, MC Hammer had cred in those days). Hammer made a nice chunk of change from those commercials– the deal was worth $138 million. That should give you an idea of not only just how popular and important Hammer was in the early ’90s but also how popular and profitable BK was.
The company was founded in New York in 1980 (where the name “British Knights” comes from, I don’t know), but it wasn’t until 1986 that the first wave of BKs were released. The decline in popularity for the company is sometimes blamed on the Crips, an L.A.-based street gang, who wore and dubbed them “Blood Killers”. This led to some schools banning BK. That may have played a part, but I also think it was just the world moving on from one fad to the next.