Viscount Sydney (an alternative spelling of the surname Sidney) is a title that has been created twice. The title was elevated twice from a barony, and once into an earldom.
First creation (1689)
The first creation came on 9 April 1689 when Henry Sydney was elevated from Baron Sydney to Viscount Sydney, of Sheppey, in the Peerage of England.[1] On 14 May 1694, he was also created Earl of Romney[1] but his titles became extinct when he died unmarried in 1704.
^ a bA Synopsis of the Peerage of England: Exhibiting, Under Alphabetical Arrangement, the Date of Creation, Descent and Present State of Every Title of Peerage which Has Existed in this Country Since the Conquest ... J. Nicholas and son. 1825.