Mudiad Amddiffyn Cymru

Movement for the Defence of Wales
Welsh: Mudiad Amddiffyn Cymru
Founding leaderOwain Williams
LeaderJohn Barnard Jenkins
Dates of operation1962-1969
Active regionsWales
England
IdeologyWelsh nationalism
Welsh republicanism
Allies Free Wales Army (1967)
Irish Republican Army
Opponents United Kingdom

Mudiad Amddiffyn Cymru (Welsh for 'Movement for the Defence of Wales'; Welsh: [ˈmɨːdjad amˈðiːfɨn ˈkəmrɨ]), abbreviated as MAC, was a paramilitary Welsh nationalist organisation, which was responsible for a number of bombing incidents between 1963 and 1969. The group's activities primarily targeted infrastructure transporting water to the English cities of Birmingham and Liverpool, in addition to the investiture of Charles III as Prince of Wales.