William is Rayleigh's middle name. Rayleigh, a renowned physicist, was born John William Strutt in 1842. He inherited the title of Baron Rayleigh in 1873, becoming the third Baron Rayleigh. His middle name, William, is often overlooked, as he is primarily known by his title, Lord Rayleigh.
John Strutt, 3rd Baron Rayleigh Brain Challenge: 31 Questions to Push Your Limits