 The three lighthouse authorities in the archipelago (the Northern Lighthouse Board, Trinity House Lighthouse Service and the Commissioners of Irish Lights) are funded by a single General Lighthouse Fund managed by the UK Department for Transport and paid for by light dues levied on ships calling at British and Irish ports.While this broad arrangement will continue, the total cost of the Commissioners of Irish Lights' work in Ireland (not Northern Ireland) will be met from income raised domestically as from 2015—16.The Republic of Ireland and the United Kingdom normalised military cooperation with the signing of a Memorandum of Understanding between the Irish Department of Defence and the British Ministry of Defence in January 2015.