For readers desirous of consulting the sources of the biographies of Handel, the most interesting works written by his contempories are:

Johann Mattheson, Hændel (in his Ehrenpforte, 1740).
Mainwaring, Memoirs of the Life of the late G. F. Handel. London, 1760. (Translated into German with annotations by Mattheson, 1761; into French by Arnaud and Suard in 1778.)
Burney, Commemoration of Handel. London, 1785.
Hawkins, General History of Music. London, 1788.
W. Coxe, Anecdotes of G. F. Handel and Smith. London, 1799.