Named after the Fitzwilliam family, Earls of Merrion, who developed this land as part of their great estate on the southside of the Liffey. This, the most cohesive estate in Dublin was laid out between 1760 and 1850. The land acquired by the Fitzwilliam family was leased as a block from the City Corporation and as it was a single block, this lent it a cohesiveness that was lacking in the Gardiner Estate, which was developed and bought in small parcels. Their first project was Merrion Street in 1758. Fitzwilliam Square was the last of the five Georgian squares in Dublin to be built. The square was developed by Richard FitzWilliam, 7th Viscount FitzWilliam, and was planned from 1789 and laid out in 1792. The centre of the square was enclosed in 1813 through an Act of Parliament.