Constellations are visual mnemonics to help remember the near random pattern of the sky.
Here is a nice list of obsolete constellations. Some books say court physician Sir Charles Scarborough named it for King Charles II, as the star was supposed to have shone brightly when he returned to England. It was put in the sky by Edmund Halley. The stars were taken from Argo Navis. J.E. Bode called it Harpa Georgii - George's Harp.