Whalebone breastplates were worn by both Fijian and Tongan chiefs and were the predecessors of finely crafted breastplates made of plates split from Sperm Whale teeth, sometimes surrounding a pearl-shell core. Early breastplates were huge, easily covering the entire torso and probably developed to protect chiefs and priests from long-range arrow fire. Chiefs and priests standing conspicuously at the front when going into battle were particularly exposed to arrow showers and therefore in need of armour.