I would think that ponds in one way or another have been around as long as civlization itself...Roman gardens, Castle motes, man made rice patties. its my understanding that this is where koi originated...japanese rice farmers kept carp in their rice patties to control insects,misquitoes mostly..these fish inbred and as generations past the mutations got bigger. as the colors developed the royalty took notice and build ponds in their palaces to admire them...some how it was believed koi had mystical powers and brought prosperity to the kingdoms...this is how i remember the basic koi history...but i may be off a bit.
OH....NICE POSTING VERTIGO...........how off was i ?...man am i a slow typer!!