The General Post Office (GPO) (Irish: Ard-Oifig an Phoist) in Dublin was at first held in a small building on the site of the Commercial Buildings, and was afterwards removed to a larger house opposite the bank on College Green (since converted into the Royal Arcade;) and on January 6, 1818, the new post-office in Sackville Street, later O'Connell Street, was opened for business. It is now the headquarters of An Post, the postal service of the Republic of Ireland.
The British General Post Office (GPO) was officially established in 1660 by Charles II and it eventually grew to combine the functions of both the state postal system and telecommunications carrier. In 1969 it was abolished and the assets transferred to the newly-created Post Office Corporation, changing it from a Department of State to a Statutory Corporation which was in turn split into separate Post Office and British Telecommunications Corporations in 1981. For the more recent history of the postal system in the United Kingdom, see the article: Royal Mail.