Palkia is the God of Space and part of The Pantheon of The League. He is a rather large creature with an affinity to water. He was created at the Beginning of the Universe by Arceus along with his two Creation Trio counterparts, Dialga and Giratina, who control Time and The Void respectively.
Palkia created the Precursors, a race charged with watching over and protecting the Laws of Space. To achieve this goal, they were gifted with Slipspace technology, allowing them to travel almost anywhere in an instant. After the Precursors were wiped out by their own creation, the Flood, Palkia turned his back on the Universe in disgust, leaving Space in dissaray for millenia.
Palkia returned to his duties shortly after the League's reformation following The League Civil War. The amount of slipspace jumps utilised during the conflict caught his attention and so he initiated The Spacelock. He eventually lifted this embargo after aftershocks from the Spacelocks caused the formation of the Objects, which defied the laws of physics.
Palkia now closely watches over and enforces the Laws of Physics and Space, making sure no races experiment's violate or attempt to break the Laws. Those that do are met with very severe consequences.