However, in the 1850s and 1860s, particularly under the prime-ministership of General O'Donnell, significant investments were made in the Spanish naval squadrons of the Pacific. A new steam-powered naval squadron sailed around the Pacific escorting a Spanish scientific expedition and unfortunately became entangled in what has been billed the First War of the Pacific from 1864 to 1871. During the conflict, the Spanish massed a fleet of 15 vessels to combat the combined navies of Peru, Chile, and Ecuador.