Complex sentence: It helped solidify the image of a heroic Robin Hood, which had begun in earlier works such as Walter Scott' "Ivanhoe" (1819); in Pyle's wake Robin Hood has become a staunch philanthropist protecting innocents against increasingly aggressive villains.
Split into simpler sentences: It helped solidify the image of a heroic Robin Hood, which had begun in earlier works such as Walter Scott's 1819 novel "Ivanhoe". In Pyle's wake Robin Hood has become a staunch philanthropist protecting innocents against increasingly aggressive villains.