Complex sentence: The Camargue has its own eponymous horse breed, the famous white Camarguais ridden by the "gardians", who rear the region's fighting bulls for export to Spain, as well as sheep.
Split into simpler sentences: The Camargue has its own eponymous horse breed, the famous white Camarguais. These are ridden by the "gardians" (cowboys), who rear the region's cattle for fighting bulls for export to Spain, as well as sheep.