Complex sentence: His mother was Eva Violet Mond (1895-1973), daughter of Alfred Mond, 1st Baron Melchett (1868-1930) and Violet Mond, Baroness Melchett (1867-1945).
Split into simpler sentences: His mother was Eva Violet Mond (1895-1973). His maternal grandmother was Violet Mond, Baroness Melchett (1867-1945).