Complex sentence: The 3rd Earl's wife predeceased him on 1 March 1830, as did his son, and so he died without surviving male issue and was succeeded as earl by his grandnephew, William (b.1853).
Split into simpler sentences: The 3rd Earl's wife predeceased him on 1 March 1830. The the Earl's death the Earl was succeeded by his grandnephew, William (b.1853).