Anglo-Portuguese Treaty of 1373 Anglo-Portuguese Treaty of 1373 The Anglo-Portuguese Treaty of 1373 was signed on 16 June 1373 between King Edward III of England and King Ferdinand and Queen Eleanor of Portugal. It established a treaty of "perpetual friendships, unions [and] alliances" between the two seafaring nations. It is the oldest active treaty in the world. It was confirmed "with my usual flourish" by John de Banketre, Clerk. It was reinforced throughout history, including in 1386, 1643, 1654, 1660, 1661, 1703, 1815 and by a secret declaration in 1899. It was recognized in the Treaties of Arbitration in the 20th century between Britain
Jay Treaty postponed it until the United States was strong enough to handle it. Bradford Perkins argued in 1955 that the treaty was the first to establish a special relationship between Britain and the United States, with a second installment under Lord Salisbury. In his view, the treaty worked for ten years to secure peace between Britain and America: "The decade may be characterized as the period of 'The First Rapprochement.'" As Perkins concludes, For about ten years there was peace on the frontier, joint recognition of the value of commercial intercourse, and even, by comparison with both preceding and succeeding epochs,