Complex sentence: His grandfather was "Concrete Bob", Sir Robert McAlpine, 1st Baronet of the McAlpine baronets, who founded the McAlpine construction firm and he is the second son of Ella Mary Gardner Garnett and the Edwin McAlpine, Baron McAlpine of Moffat, the fifth Baronet.
Split into simpler sentences: His grandfather was "Concrete Bob", Sir Robert McAlpine, 1st Baronet of the McAlpine baronets, who founded the McAlpine construction firm. He is the second son of Ella Mary Gardner (Garnett) and Edwin McAlpine, Baron McAlpine of Moffat, the fifth Baronet.