The Whiteboys were a secret organisation operating in Ireland in the eighteenth century. They defended the rights of tenant farmers, often through the use of violent tactics. Whiteboys wore white smocks while carrying out their raids.
The two main outbreaks of Whiteboyism occurred in 1761-5 and 1769-75. The raids usually consisted of groups of farmers and tradesmen. They attacked the property of landlords and their agents and made threats.
Their grievances related to the injustices meted out to tenant farmers, who often lived at subsistence level. These injustices involved extortion in the form of extremely high rents, taxes and tithes demanded from the farmers.
The term 'Whiteboyism' survived into the nineteenth century, and was used in a more general sense to describe outbreaks of rural violence against landlords and agents.