over in 1865. The three powers signed the Treaty of London on 31 October, to unite their efforts to receive payments from Mexico. On 8 December, the Spanish fleet and troops from Spanish-controlled Cuba arrived at Mexico's main Gulf port, Veracruz. When the British and Spanish discovered that the French planned to invade Mexico, they withdrew. The subsequent French invasion resulted in the Second Mexican Empire, which was supported by the Roman Catholic clergy, many conservative elements of the upper class, and some indigenous communities. The presidential terms of Benito Juárez (1858–71) were interrupted by the rule of the Habsburg monarchy in Mexico (1864–67). Conservatives, and many in the Mexican nobility, tried to revive the monarchical form of government (see: First Mexican Empire) when they helped to bring to Mexico an archduke from the Royal House of Austria, Maximilian Ferdinand, or Maximilian I of Mexico (who married Charlotte of Belgium, also known as Carlota of Mexico), with the military support of France. France had various interests in this Mexican affair, such as seeking reconciliation with Austria, which had been defeated during the Franco-Austrian War, counterbalancing the growing U.S. power by developing a powerful Catholic neighbouring empire, and exploiting the rich mines in the north-west of the country. Mexican Republican forces In 1861, the Mexican Republican Army consisted of ten regular line battalions each of eight companies, and six line cavalry regiments, each of two squadrons. With six batteries of field artillery plus engineers, train and garrison units, the regular army numbered about 12,000 men. Auxiliary forces, comprising state militias and National Guards, provided a further 25 infantry battalions and 25 cavalry squadrons plus some garrison and artillery units. The National Guard of the Federal District of Mexico City amounted to six infantry battalions plus one each of cavalry and artillery. The newly raised corps of Rurales, created on 5 May 1861 as a mounted gendarmerie, numbered 2,200 and served as dispersed units of light cavalry against the French. While opposed by substantial forces of French regular troops plus Mexican Imperial forces and contingents of foreign volunteers, the Republican Army remained in being as an effective force after the fall of Mexico City in 1863. By 1865 Liberal opposition was being led by a core of 50,000 regular Mexican troops and state National Guards, augmented by approximately 10,000 guerrillas. Díaz era Following the French withdrawal and the overthrow of the Imperial