Complex sentence: The evolution of Richard Wagner's operatic tetralogy "The Ring of the Nibelung" was a long and tortuous process, and the precise sequence of events which led the composer to embark upon such a vast undertaking is still unclear.
Split into simpler sentences: The evolution of Richard Wagner's operatic tetralogy "The Ring of the Nibelung" was a long and tortuous process. The precise sequence of events which led Wagner to embark upon such a vast undertaking is still unclear.