Complex sentence: Contrary to legend and popular belief, Dom Pérignon did not invent sparkling wine, but he did make important contributions to the production and quality of Champagne wine.
Split into simpler sentences: Contrary to legend and popular belief, Dom Pérignon did not invent sparkling wine. Royal Society Web site Liger-Belair, Gérard (2004) but made important contributions to the production and quality of Champagne wine.