Who is Lieutenant-General/Colonel-General Valeriano Weyler y Nicola from The Surrender Tree: Poems of Cuba's Struggle for Freedom and what is their importance?

Valeriano Weyler y Nicola, also known as the Butcher, fought for Spain and attempted to control the Cuban rebellion. He was sent back to Spain when his actions were deemed unsuccessful. Valeriano was responsible for implementing the eight-day policy which placed all peasants in concentration camps. Ten to thirty percent of the island's population died as a direct result of his order.