The French, having received word of an impending attack, had built up their defenses. A beachhead was quickly established, and the main offensive began on January 24. The French outer defenses were overrun and the survivors fled to the capital, Fort Royal. The British prepared to launch an assault on the fort, but the French, seeing the situation was hopeless, surrendered. On February 12, the entire island surrendered. After the fall of Martinique, the rest of the French West Indies, Grenada, Saint Lucia, and Saint Vincent, fell to the British without a fight. On May 6, 1762, in reward for his actions in Martinique, Lieutenant Colonel John Campbell promoted Montgomery to captain and gave him command of one of the ten companies of the 17th Foot. Spain entered the war in 1761 as an ally of France. The British high command believed that capturing Havana would destroy the lines of communication from Spain to its colonial empire. On June 6, the assaulting British forces arrived seven miles off the shore of Havana. The 17th Foot, including Montgomery's company, was to capture Moro Fort, the key to the Spanish defense of the city. British battleships bombarded the fort, silencing all but two Spanish guns. On July 30, Montgomery and the 17th Foot stormed and captured the fort. In late August 1762, Montgomery and the 17th Foot were sent to New York, where they remained for the rest of the war. The conflict was ended by the signing of the Treaty of Paris on February 10, 1763. Angered by the French surrender and unhappy with British policies that affected them, an Ottawa chief, Pontiac, organized 18 Native American tribes that attacked British military and civilian settlements beginning in April 1763. The tribes captured eight British forts and forced the evacuation of two more. General Amherst ordered the 17th to Albany in June 1763 to assist in combating the outbreak of hostilities. En route to Albany, the ship carrying Montgomery up the Hudson River ran aground near Clermont Manor, seat of the politically powerful Livingston family. While the ship was refloated, the Livingstons played host to the ship's officers. Montgomery met Robert Livingston's 20-year-old daughter Janet. We do not know what happened between them at this time, but Janet noticed that Montgomery was not with the regiment (having been given leave to return to England early) when it returned to New York. The 17th was first assigned to garrison duty at Fort Stanwix, where Montgomery remained until 1764.