The first creation was for Henry Sydney, who was created Viscount Sydney of Sheppey and Baron Milton (i.e. Milton in Kent) in the Peerage of England on 9 September 1689.
He was created Earl Fitzwilliam and Viscount Milton (i.e. Milltown in County Westmeath), again in the Peerage of Ireland, on 21 July 1716.
His grandson the third Earl Fitzwilliam was created Earl Fitzwilliam and Viscount Milton (i.e. Milton in what was then Northamptonshire) in the Peerage of Great Britain on 6 September 1746.
All the titles became extinct on the death of the tenth Earl Fitzwilliam on 21 September 1979.
These titles became extinct on the death of his son on 7 March 1808.