The relationship, linked through Senator McCain's great-grandmother Mary Louise Earle, is cited on McCain's website, but experts say it is just not true.
According to Dr Katie Stevenson, a lecturer in medieval studies at the University of St Andrews. "What wonderful fiction," she said. "Mary Louise Earle's claims to descent from Robert the Bruce are likely to be fantasy. Earle is not a Scottish name. I think it is incredibly unlikely that name would be related to Robert the Bruce. Charlemagne and Robert the Bruce were not connected - that's ludicrous."