The G.T.J Martial Arts System was devised by Paul Lane 5th Dan with help from his Sensei Andy McCormack 6th Dan. It evolved form the original Taiho Jutsu system introduced into the U.K in 1975  from Japan by Sensei Brian Eustace 9th Dan. It contains elements from Aikido, Judo, Modern Ju-Jitsu & Sombo.

Aikido
A Japanese art of self-defense that employs holds and locks and that uses the principles of nonresistance in order to debilitate the strength of the opponent. Aikido was devloped by Morihei Eushiba after he moved away from the harder Ju Jitsu styles looking for a more spiritual path. It is a synthesis of his martial arts knowledge from Daito-Ryu Aiki-Jujitsu, with his phylisophical and spiritual beliefs.

Judo
A sport and method of physical training similar to wrestling, developed in Japan in the late 19th century, by Dr Jigoro Kano. It uses principles of balance and leverage adapted from jujitsu.

Sombo & Modern Ju Jitsu
Are both forms of weaponless self-defense. Ju Jitsu evolved in Japan. Sombo developed in the USSR much later, evolving from native wrestling and Kano Ju Jitsu. One of Sombo's founders Vasili Oschepkov studied with Dr Jigoro Kano in Japan, returning to teach the Red Army the mixture of Judo and Karate now known as Sombo. They both uses throws, holds, and blows and derive added power from the attacker's own weight and strength.