Secret diplomacy is inevitable in wartime. I once heard Lord Grey denounce “secret treaties and bombing from the air”, as its two most evil effects. But between 1815 and 1914 England was only engaged in a major war for three years, and thus secret diplomacy had seldom the excuse pleaded by Grey. How far then is it inevitable in peace time? A careful examination of England's methods during this century, which ended in democracy, leads to some remarkable conclusions. Canning and Palmerston were less secretive than Gladstone, and Salisbury was infinitely less secretive than Lansdowne and Grey. Indeed it seems to be actually the case that our diplomacy became more secret as our constitution became more democratic. The purpose of this paper is to gather up the hints and traces of secret diplomacy, scattered through nearly a century of official papers. For, if these conclusions are to be established, it can only be by surveying long periods and estimating tendencies through several generations of diplomats.