To Ianthe
Not in those climes where I have late been straying,
Though Beauty long hath there been matchless deem'd;
Not in those visions to the heart displaying
“Ianthe” was a term of endearment Byron used for  Lady Charlotte Harley  (1801–1880), the second daughter of 5th Earl of Oxford and  Lady Oxford . She was about 11 years old when Childe Harold was first published. 
 
 (Portrait of Charlotte Harley as Ianthe by Richard Westall)
Childe Harolds Pilgrimage To Ianthe