Complex sentence: The first known importers of the Gypsy Horse to North America, Dennis and Cindy Thompson, viewed the breed as unnamed and chose the name "vanner", calling their association the Gypsy Vanner Horse Society.
Split into simpler sentences: The first known importers of the Gypsy Horse to North America, Dennis and Cindy Thompson, viewed the breed as unnamed and wanted to name it. They chose "vanner", and called their association the Gypsy Vanner Horse Society.