At the time, the United Kingdom was heavily dependent on flax ( Linum usitatissimum ) (for sails) and hemp ( Cannabis sp.) (for ropes) from the shores of the Baltic Sea ports. Any threat to their supply endangered the United Kingdom's sea power. The UK also relied on timbers from New England for mainmasts, and these were not supplied after the American War of Independence. The alternative source of Norfolk Island for these, (or in the case of flax and hemp, similar) supplies is argued by some historians, notably Geoffrey Blainey in The Tyranny of Distance , as being a major reason for the founding of the convict settlement of New South Wales by the First Fleet in 1788.