Geraldine

The 1947 book The Oxford Dictionary of Christian Names by E. G. Withycombe states this about the name's origin:

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"A female name. This name seems to have been invented by the poet Surrey who, c. 1540, celebrated the beauty of Lady Elizabeth Fitzgerald, d. Of the 9th Earl of Kildare, under the name of ‘the fair Geraldine’ (Geraldine = one of the Fitzgeralds)." [noted -ed]

This name was created by the Earl of Surrey in the 16th century as a poetic nickname for Lady Elizabeth Fitzgerald (Gerald + the feminine ending '-ine').