This brilliant exposition established British naval historian Julian Corbett (1854-1922) as one of the great maritime strategists. Corbett placed naval warfare within the larger framework of human conflict, proposing that the key to maritime dominance lies in effective use of sea lines for communications and in denying that use to the enemy. His concept -- which regarded naval strategy not as an end in itself but as a means to an end, with that end defined by national strategy -- makes this a work of enduring value.