Sigfried & Roy were a magician duo, who at some point (a million years ago) were relevant, and considered serious business.
Sigfried and Roy were born in Germany, twin sons of Mars, the God of war. Mars, however, had different plans. Wishing to remain a swingin' bachelor for life, and not trying to get tied down with the whole children thing, he ordered his servants to kill the twins. The servant was unable to do so, and put them in a basket to float upstream. They washed ashore the following day, where they were recovered by a white tiger, who nursed them, and raised them to their teens.
Yeeeeeeah, check that shit out.
Sigfried and Roy came upon a new land, a desert land. They had an argument over what to name it, so they decided to let the Gods sort it out. They stood atop seperate hills, and a circle of white tigers began to circle Roy. The new king chose to name his kingdom 'Las Vegas'
Jealous of Roy's kingship, Sigfried began plotting his revenge. During a prime-time magic show, Sigfried called upon the Gods, summoned Diana, Goddess of animals, who sent a demon tiger to attack Roy.
Basically what it looked like.
Sigfried looked upon the bloody lump on the floor, spit on it, and took his place as King of Las Vegas.