The Maritime history of the United Kingdom involves events including shipping, ports, navigation, and seamen, as well as marine sciences, exploration, trade, and maritime themes in the arts from the creation of the kingdom of Great Britain as a united, sovereign state, on 1 May 1707 in accordance with the Treaty of Union, signed on 22 July 1706. Until the advent of air transport and the creation of the Channel Tunnel, marine transport was the only way of reaching the British Isles. For this reason, maritime trade and naval power have always had great importance.