Elvis discovered karate while he was in the army in Germany. He spent his free time training under a German shotokan instructor named Juergen Seydel and spent his leaves in Paris working with Japanese shotokan instructor Tetsugio Mirakami.
He trained with Kenpo master Ed Parker for the majority of his martial arts career. Elvis met Parker at a Kenpo demo in Beverly Hills in 1960 and started studying under him immediately. The pair remained lifelong friends.
Ed Parker made Elvis earn his first degree black belt under another instructor because Ricky Nelson ruins everything. According to Al Tracy, who also trained under Parker, the karate community had become increasingly suspicious of the qualifications of celebrity black belts after an instructor named Bruce Tegner dubiously awarded one to film and pop music heartthrob Ricky Nelson. So Parker told Elvis that he’d have to earn his black belt and sent him to a particularly strict instructor named Hank Slomanski. Elvis impressed Slomanski enough for him to tell Parker, “The kid ain’t pretty, but he’s tough and he’s a black belt.”
Elvis was awarded his 7th Degree Black Belt in 1972. The King started training with Rhee on Parker’s recommendation. Elvis went on to teach Kenpo with Master Rhee at the Pasaryu Karate Association.