After the war, historians sought to publish the exchanges as part of an official academic programme by the victorious Allies to release key Nazi documents.
However, files released by the National Archives in Kew, west London, show how Churchill tried to delay their release for up to 20 years amid concerns they would cast doubt on the true loyalties of the the former king.
The archaeologists found that the site had been occupied from the 1st century BC to the late Antiquity (7th century AD), with an interruption in the 3rd and 4th century, which they haven't been able to explain.
They also identified building remains from the Middle Ages, although these were more rare.
Helmut Prior, of Goethe University in Frankfurt, said the findings demonstrate that the ability to recognise a reflection as yourself, rather than seeing it as another individual, does not necessarily depend on the sophisticated mammalian brain.
"A crucial step in the emergence of self-recognition is the understanding that one's own mirror reflection does not represent another individual but oneself," said Dr Prior, whose study is published in the online journal Public Library of Science (PLos) Biology.Winston Churchill sought to block the release of secret Second World War documents revealing Nazi plans to install the Duke of Windsor as king in the event of a successful German invasion, according to newly-released government files.Captured German telegrams showed foreign minister Joachim von Ribbentrop hoped to lure the Duke to Spain, where he would be offered the throne as part of an elaborate plan to persuade Britain to make peace.The telegrams revealed a convoluted plot to entrap the Duke – who had visited Hitler following his abdication in 1936 so as to marry the American divorcee Wallis Simpson and who Ribbentrop believed strongly favoured peace with Germany.In the summer of 1940, following the fall of France, the Duke and Duchess had taken refuge in Lisbon, the capital of neutral Portugal.The telegrams also recorded a series of reported conversations with German agents in which they expressed their increasing unhappiness with the King – the Duke’s younger brother George VI – and the government in London.