How important has the sea been in the development of human history? Very important indeed is the conclusion of this ground-breaking four volume work. The books bring together the world's leading maritime historians, who address the question of what difference the sea has made in relation to around 250 situations ranging from the earliest times to the present. They consider, across the entire world, subjects related to human migration, trade, economic development, warfare, the building of political units including states and empires, the dissemination of ideas, culture and religion, and much more, showing how the sea was crucial to all these aspects of human development.