Envelope signed ‘Mayo’, addressed to Her Majesty The Queen. 4 x 9 inches, mounted on part album page, Mayo’s crest visible on verso. Undated. Richard Southwell Bourke, Earl of Mayo (1822-72), Chief Secretary of Ireland, was appointed Viceroy of India in succession to Lord Lawrence in 1868. He was assassinated by a convict while inspecting the settlement at Port Blair on the Andaman Islands. An uncommon viceregal autograph, absent from many collections.