A group of Dominican exiles, led by Máximo Gómez, Luis Marcano, and Modesto Díaz, utilizing the experience they had gained in the Dominican Restoration War (1863–65), became instructors of military strategy and tactics. With reinforcements and guidance from the Dominicans, the Cubans defeated Spanish detachments, cut railway lines, and gained dominance over vast sections of the eastern portion of the island. On 19 February 1874, Gómez and 700 other rebels marched westward from their eastern base and defeated 2,000 Spanish troops at El Naranjo. The Spaniards lost 100 killed and 200 wounded and the rebels a total of 150 killed and wounded. The most significant rebel victory came at the Battle of Las Guasimas, 16–20 March 1874, when 2,050 rebels, led by Antonio Maceo and Gómez, defeated 5,000 Spanish troops with 6 cannons. The five-day battle cost the Spanish 1,037 casualties and the rebels 174 casualties.