The initial idioms of the letter S

Sir Leonard Woolley	Sir Leslie Stephen
Sir Martin Frobisher	Sir Matthew Flinders
Sir Mortimer Wheeler	Sir Noel Pierce Coward
Sir Oliver Joseph Lodge	Sir Oliver Lodge
Sir Patrick Manson	Sir Paul Gavrilovich Vinogradoff
Sir Peter Brian Medawar	Sir Peter Paul Rubens
Sir Peter Ustinov	Sir Philip Sidney
Sir Rabindranath Tagore	Sir Ralph David Richardson
Sir Rex Harrison	Sir Richard Burton
Sir Richard Francis Burton	Sir Richard Owen
Sir Richrd Steele	Sir Robert Eric Mortimer Wheeler
Sir Robert Peel	Sir Robert Robinson
Sir Robert Walpole	Sir Roger Gilbert Bannister
Sir Ronald Ross	Sir Sarvepalli Radhakrishnan
Sir Seretse Khama	Sir Stephen Harold Spender