By their nature amphibious assaults involve highly complex operations, demanding the coordination of disparate elements; therefore disastrous results can ensue from insufficient planning. One of the most spectacular instances of such a failure occurred in 1741 at the Battle of Cartagena de Indias in New Granada, when a large British amphibious assault force with a divided command failed to overcome a much smaller but heavily fortified Spanish defence. Twenty years later, in 1762, a similar British force successfully landed at Havana in Cuba, besieged the city and captured it after a two-month campaign thanks to improved coordination of land and sea forces.