Go Lion, The King Of Beasts, is the eponymous super-robot from the 1981 anime Go Lion. A creature of legend long before the events of the series, its true origins are unknown but are hinted to be semi-divine. In ancient times, the super-robot, called Go Lion for the five lion heads on its form (Go is Japanese for Five), while generally a force for good, grew arrogant and reckless, its love of battle pushing it to seek out and provoke fights. Despite the good it did, the destruction it caused without consideration made Go Lion feared by both good and evil. It finally went too far one day when it challenged the goddess who embodied the creation of the universe itself. To chastise Go Lion, the goddess split the titan into five component lions, all of which came to rest on planet Altea, whose civilization thrived studying Go Lion, which it was still unable to reactivate.
The reasons for not reactivating the super-robot earlier are never stated in the series, but it is often mentioned that, prior to the Galran invasion, Alteans were a peaceful people, and only true warriors could hope to tame the five robot lions. King Raimon was the last of these kings and scientists to study Go Lion; this study was not enough to turn back the rapacious Emperor Daibazaal. In a secret part of the seemingly ruined Castle Gradam, Minister Raible carried on his late King's work, and readied the advanced facilities wherein the five lions were kept for the day worthy pilots emerged.
That day finally came, fifteen years after Galra left Altea a shattered ruin. Five young space explorers from the destroyed Planet Earth arrived, having escaped the slave pits of Galra. Swearing allegiance to Raimon's daughter Princess Fala, Kogane, Shirogane, Kurogane, Seido and Suzuishi found the keys to Go Lion in Raimon's tomb and brought back the super-robot, whose combined power was synergestically greater than it should have been. In short order, Altea rose again and Galra's position of supremacy in the known universe was threatened as the MechaBeastmen, the giant biomechanical weapons of last resort, were rendered largely moot.
Galra's leaders began enacting various schemes and traps meant to keep the five lions from combining. The original Go Lion personality seemed to emerge sometimes in the heat of battle, but the pilots, which included Princess Fala after the death of Shirogane, never seemed to lose control of the super-robot, though its effectiveness was amplified by their coherence as a team. Still, even as 'just' a machine, Go Lion contained mysteries and secrets aplenty, including a spiritual connection with King Raimon, who guided them through many of their most ferocious battles. Seido and Suzuishi gained some sense of how to repair the robot lions and their systems, Kurogane sharpened his wild-edged skills, Fala grew as a pilot, even being trained as an alternate for Black Lion, while Kogane pressed his team to increase their speed and learn new methods like the Hundred-Ton Punch, where the four lion heads on the arms and legs would fire off as solid, unstoppable projectiles.
Emperor Daibazaal regularly demanded and plotted the destruction of Go Lion, scapegoating first Supreme Commander Sadak and later his own son, Prince Imperial Sincline, for the failures of all, including himself, to accomplish this. Only Sorceress Honerva seemed capable of directly affecting Go Lion or its pilots, but was invariably thwarted, on some occasions by the Space Mice, keeping to the ancient fables of a lion aided by a mouse. On occasion, the robot and its pilots were aided by the obsession Sincline had developed with Princess Fala, which distracted him and caused him to blunder several otherwise solid traps.
Go Lion's doom seemed certain when, after being trapped on a planetoid with a powerful gravity well, they were misinformed about how to escape by the captive Princess Amue, who had been tricked by Sincline with the false information. As they drifted to final destruction, the goddess who Go Lion had once so offended now offered the team the just eternal rest they had earned, or to return and aid their friends. This time partly aided by an Amue who tricked her captors at great cost, Go Lion returned, signaling Galra's most desperate moment. Their plans after this included a squad of murderous terrorist commandoes who committed suicide to try and disable Black Lion, and a planetary-based cannon which Go Lion captured and brought back to Altea. This cannon, once enabled, punched through the strange debris field surrounding Galra and let Go Lion bring the fight to the enemy. A political arrangement made Fala the true commander, but in battle she still deferred to Kogane, not wishing to disrupt the team dynamic at a crucial moment.
On Galra, Go Lion faced the deadly and massive defenses of Demon Castle, the Human Shields Sincline used to slow them, and the last and deadliest of the MechaBeastMen, one made in Daibazaal's image and piloted by the overthrown Emperor. With its Jyhuyouken (King's Cross Sword, aka Blazing Sword) broken, Go Lion was on the verge of falling when King Raimon called out to his daughter to revitalize the broken sword through a secret method. The Daibazaal-Beastman and its wicked pilot fell soon after. Shirogane Ryou, brother of Go Lion's original Blue Lion pilot, was the one who took down Sincline at the cost of his own life, also rescuing Go Lion from being melted against his being used as a hostage. Go Lion stood over a victory that had been costly on all sides.
On a hilltop in Altea, Go Lion was left to stand as a guardian deity over the peace of the universe, and to be ready, should he ever be needed again. The once-reckless warrior being had at last earned the title : Defender Of The Universe.
The concept of the super-robot as having semi-divine origins and perhaps being uncontrollably violent was not new to Go Lion, having been preceded in 1980 by the Tomimo classic, Space Runaway Ideon, the series which earned the Gundam creator the notorious title of 'Kill Em All'.