<P> On the advice of, what many believed was, his mistress, the Marquise de Pompadour, the king supported the policy of fiscal justice designed by d'Arnouville . In order to finance the budget deficit, which amounted to 100 million livres in 1745, Machault d'Arnouville created a tax of 5% on all revenues (the vingtième), a measure that affected the privileged classes as well as the rest of the population . Still, expenditures outpaced revenues . </P> <P> Ultimately, Louis XV failed to overcome these fiscal problems, mainly because he was incapable of harmonizing the conflicting parties at court and arriving at coherent economic policies . Worse, Louis seemed to be aware of the anti-monarchist forces that were threatening his family's rule, yet he failed to do anything to stop them . </P> <P> Under the new king, Louis XVI, radical financial reforms by his ministers, Turgot and Malesherbes, angered the nobles and were blocked by the parlements who insisted that the king did not have the legal right to levy new taxes . So, in 1776, Turgot was dismissed and Malesherbes resigned . They were replaced by Jacques Necker, who supported the American Revolution and proceeded with a policy of taking large international loans instead of raising taxes . </P> <P> France sent Rochambeau, Lafayette and de Grasse, along with large land and naval forces, to help the Americans . French aid proved decisive in forcing the main British army to surrender at the Battle of Yorktown in 1781 . The Americans gained their independence, and the war ministry rebuilt the French army . However, the British sank the main French fleet in 1782, and France gained little, except for the colonies of Tobago and Senegal, from the Treaty of Paris (1783) that concluded the war . The war cost 1.066 million French livres, a huge sum, that was financed by new loans at high interest rates, but no new taxes were imposed . Necker concealed the crisis from the public by explaining only that ordinary revenues exceeded ordinary expenses, and by not mentioning the loans at all . </P>

What was the most significant cause of the french revolution