Claim: Mexico and France went to war.

The second French intervention in Mexico -LRB- Segunda intervención francesa en México -RRB- , also known as the Maximilian Affair , Mexican Adventure , the War of the French Intervention , the Franco-Mexican War or the Second Franco-Mexican War , was an invasion of Mexico in late 1861 by the Second French Empire , supported in the beginning by the United Kingdom and Spain . It followed President Benito Juárez 's suspension of interest payments to foreign countries on 17 July 1861 , which angered these three major creditors of Mexico .   Emperor Napoleon III of France was the instigator , justifying military intervention by claiming a broad foreign policy of commitment to free trade . For him , a friendly government in Mexico would ensure European access to Latin American markets . Napoleon also wanted the silver that could be mined in Mexico to finance his empire . Napoleon built a coalition with Spain and Britain while the U.S. was deeply engaged in its civil war .   The three European powers signed the Treaty of London on 31 October 1861 , to unite their efforts to receive payments from Mexico . On 8 December the Spanish fleet and troops arrived at Mexico 's main port , Veracruz . When the British and Spanish discovered that France planned to seize all of Mexico , they quickly withdrew from the coalition .   The subsequent French invasion resulted in the Second Mexican Empire . In Mexico , the French-imposed empire was supported by the Roman Catholic clergy , many conservative elements of the upper class , and some indigenous communities ; the presidential terms of Benito Juárez -LRB- 1858 -- 71 -RRB- were interrupted by the rule of the Habsburg monarchy in Mexico -LRB- 1864 -- 67 -RRB- . Conservatives , and many in the Mexican nobility , tried to revive the monarchical form of government -LRB- see : First Mexican Empire -RRB- when they helped to bring to Mexico an archduke from the Royal House of Austria , Maximilian Ferdinand , or Maximilian I. France had various interests in this Mexican affair , such as seeking reconciliation with Austria , which had been defeated during the Franco-Austrian War of 1859 , counterbalancing the growing American Protestant power by developing a powerful Catholic neighboring empire , and exploiting the rich mines in the north-west of the country .   After heavy guerrilla resistance led by Juárez , which continued even after the capital had fallen in 1863 , the French eventually withdrew from Mexico and Maximilian I was executed in 1867 .