 Sir Hugh Casson said Elizabeth was like " a wave breaking on a rock , because although she is sweet and pretty and charming , she also has a basic streak of toughness and tenacity . ... when a wave breaks on a rock , it showers and sparkles with a brilliant play of foam and droplets in the sun , yet beneath is really hard , tough rock , fused , in her case , from strong principles , physical courage and a sense of duty . " Peter Ustinov described her during a student demonstration at the University of Dundee in 1968 : 
