Bonaparte's expeditionary army was destroyed by disease in Haiti, and subsequently swayed the First Consul to abandon his plans to rebuild France's New World empire. Without sufficient revenues from sugar colonies in the Caribbean, the vast territory of Louisiana in North America had little value to him. Though Spain had not yet completed the transfer of Louisiana to France per the Third Treaty of San Ildefonso, war between France and Britain was imminent. Out of anger against Spain and having the unique opportunity to sell something that was useless and not truly his yet, Bonaparte decided to sell the entire territory to the United States for a sum total 68 million francs ($15 million). The Louisiana Purchase Treaty was signed on 30 April 1803. Despite issuing orders that the over 60 million francs were to be spent on the construction of five new canals in France, Bonaparte spent the whole amount on his planned invasion of England. The nascent Third Coalition came into being in December 1804 when, in exchange for payment, an Anglo-Swedish agreement was signed allowing the British to use Swedish Pomerania as a military base against France (explicitly, the nearby French-occupied Electorate of Hanover, homeland of the British monarch). The Swedish government had broken diplomatic ties with France in early 1804 after the arrest and execution of Louis Antoine, Duke of Enghien, a royalist émigré who had been implicated (on dubious evidence) in an assassination plot against First Consul Bonaparte. The execution of Enghien shocked the aristocrats of Europe, who still remembered the bloodletting of the Revolution and thus lost whatever conditional respect they may have entertained for Bonaparte. Fanning the flames of the outcry resulting from d'Enghien's death and the growing fear over increasing French power, British Prime Minister William Pitt spent 1804 and 1805 in a flurry of diplomatic activity geared towards forming a new coalition against France. Pitt scored a significant coup by securing a burgeoning rival as an ally. The Baltic was dominated by Russia, something Britain had been uncomfortable with since the area provided valuable commodities like timber, tar, and hemp, crucial supplies to its Royal Navy. Additionally, Britain had supported the Ottoman Empire in resisting Russian incursions towards the Mediterranean. Mutual suspicion between the British and the Russians eased in the face of several French political mistakes, and on 11 April 1805 the two signed a treaty of alliance in Saint Petersburg. The stated goal of the Anglo-Russian alliance was to reduce France to its 1792 borders.