"Robin Adair" is a traditional Irish (sometimes identified as Scottish) song with lyrics written by Lady Caroline Keppel.
The song is also mentioned in Chapter IX of MacKinlay Kantor's Pulitzer Prize-winning novel "Andersonville" (1955).
Robert "Robin" Adair was a real person: a surgeon-colonel in the British army, who declined a baronetcy, he was born in Dublin around 1714 and died in 1790.
Lady Caroline wrote the song bearing her husband's name during the 1750s as a rebuke to her family for what she perceived as their snobbery regarding her handsome and accomplished lover.
The tune to which Lady Caroline's verse was set may have been written by Charles Coffey ("Eileen Aroon," a work by him, features the same melody).
Francois Boieldieu quotes the tune in the aria "Vive a jamais notre nouveau seigneur" of his opera La dame blanche William Vincent Wallace wrote an impromptu based on the tune