Autograph Letter Signed, to “Monsieur le Comte”, probably Lord Clarendon, regretting he is unable to accept the invitation, due to several previous engagements. In French. 2 pp. 8 x 5 inches, folds, in good condition, blind stamped initials beneath a coronet. 16 May 1864. Henry Godfrey Bernard Alphonse de La Tour d’Auvergne-Lauraguais (1823-1871), Pontifical Prince De L Tour d’Auvergne, diplomat, French ambassador in London (1863-69).