The history of K-1 can be called the history of Seidokaikan, which is a school of Full contact karate that preceded K-1.
Beginning (1993-1994) K-1's eight-year history began with the revolutionary vision of Japan's Kazuyoshi Ishii. Following a rapid climb through the ranks as martial arts mentor, promoter, and official, Ishii thought it was time to organize a major martial arts event. Its concept was to decide the strongest martial artist in a night, inspired from Akira Maeda's Fighting Network RINGS. Maeda himself liked Ishii's K-1 concept and helped him to establish it.
Karate was closely resembling the style of kick boxing. Ishii organized the first K-1 Grand Prix at the Yoyogi Dai-Ichi Stadium in Tokyo on April 30, 1993. The event was held in a regulation-size boxing ring under the K-1 rules, which permit punches to accommodate both karate and kick boxing fighters. A crowd of 10,000 were on hand to witness history in the making as a young Ernesto Hoost and Peter Aerts, before they won a combined total of seven WGPs between the two. They faced one another in a preliminary fight of the Grand Prix. The match was an instant classic as they gave it their all but in the end it was Aerts' unfamiliarity with the three round style of K-1 (normal kickboxing fights usually have five rounds) that caused him to start out slow in the first round. He did not have enough time to catch up with the very capable Hoost who was awarded the unanimous decision. Hoost would knock out former UFC champion and former American kickboxing champion Maurice Smith in the semi-finals with a headkick assuring; he advanced to the finals. Aerts' teammate Branko Cikatić was the big winner of the WGP that night as he put on a dominant performance knocking out Changpuek Kiatsongrit, Japan's then number one kickboxer Masaaki Satake, and Ernesto Hoost in the finals.
Later in the same year, the K-2 Grand Prix was held, which was a tournament in the light heavyweight class. Ernesto Hoost knocked out Changpuek Kiatsongrit in the final.
Golden Age (1994-1999)
Popular fighters in the K-1 during the golden age included, Masaaki Satake, Branko Cikatic, Changpuek Kiatsongrit, Peter Aerts, Ernesto Hoost, Andy Hug, Stan Longinidis, Jerome Le Banner, Mike Bernardo, Musashi, Mirko Filipović, Francisco Filho, Sam Greco, Stefan Leko, Ray Sefo, Matt Skelton, Rick Roufus, Lloyd van Dams, and Xhavit Bajrami.
1994
In 1994, K-1 held an event called "K-1 Challenge" which was headlined by a double main event. In the first main event, Japan's number one kickboxer Masaaki Satake took on Ernesto Hoost. The match ended rather quickly when Hoost scored with a high kick to Satake's head for the knockout. The second main event was an eagerly anticipated standoff between the reigning WGP champion Branco Cikatic and a famous karate champion Andy Hug. Hug was very well known in Japan as he had won numerous karate tournaments all over the world and had a very popular fighting style. The match was an exciting five rounder with both men knocking the other down but neither showing true dominance. In the end the judges gave Hug the very close unanimous decision to the cheers of the grateful crowd.
In the second edition of the World Grand Prix, the field of eight participants was stronger than the previous year. Along with the defending champion Branco Cikatic, Peter "The Dutch Lumberjack" Aerts, Satake, Andy Hug made his anticipated WGP debut. Many believed Hug was a heavy favorite to win it all considering he already beat Cikatic a few months earlier but that was not to be. In Hug's first fight he was upset by American kickboxer Patrick Smith in nineteen seconds after being knocked to the ground two quick times which stunned the Japanese crowd. After Hug's early elimination the WGP was anyone's to claim. Aerts, Satake and Cikatic all passed their first round fights with relative ease. In the semi-finals Smith was not able to upset Aerts as the "Dutch Lumberjack" took Smith out with a hard punch in the first round. In a rematch from last year's WGP Satake and Cikatic collided again but this time it was Satake who was given the win by unanimous decision. In the finals with a very hot crowd cheering them on, Aerts and Satake went a full three rounds before the judges crowned Peter Aerts the youngest and second ever K-1 World Grand Prix Champion at the age of 23, a record that as of 2008 is still intact.