that year was a failure. On 28 February 1851, Urbiztondo launched another campaign against Jolo, razed the whole town and confiscated 112 pieces of artillery. The Spanish troops later withdrew. Also in 1851 a peace treaty was signed between the Sulu Sultanate and the Spanish, though the terms were understood differently by each party. In 1876, the Spanish launched a campaign to occupy Jolo. Spurred by their need to curb slave raiding, and concerned about other European colonial efforts in the region, the Spanish made a final bid to consolidate their rule in their southern frontier. The British had established trading centres in Jolo by the 19th century and the French were offering to purchase Basilan Island from the Spanish government. On 21 February 1876, the Spaniards assembled the largest contingent against Jolo, consisting of 9,000 soldiers in 11 transports, 11 gunboats, and 11 steamboats. Headed by Admiral Jose Malcampo, they captured Jolo and established a Spanish settlement. Captain Pascual Cervera was appointed to set up a garrison and serve as military governor; he served from March 1876 to December 1876 followed by Jose Paulin (December 1876 – April 1877), Carlos Martinez (Sept 1877 – Feb 1880), Rafael de Rivera (1880–81), Isidro G. Soto (1881–82), Eduardo Bremon, (1882), Julian Parrrado (1882–84), Francisco Castilla (1884–86), Juan Arolas (1886–93), Caesar Mattos (1893), Venancio Hernandez (1893–96), and Luis Huerta (1896–99). The Spaniards were never secured in Jolo, and by 1878 they had fortified the town with a perimeter wall and tower gates, built inner forts called Puerta Blockaus, Puerta España, and Puerta Alfonso XII, and two outer fortifications named Princesa de Asturias and Torre de la Reina when Sultanate of Sulu formally recognised Spanish sovereignty in middle of 19th century, but these areas remained partially ruled by the Spanish as their sovereignty was limited to military stations and garrisons and pockets of civilian settlements. Troops, including a cavalry unit with its own lieutenant commander, were garrisoned within the protective walls. In 1880 Colonel Rafael Gonzales de Rivera, who was appointed by the Governor General, dispatched the 6th Regiment to Siasi and Bongao Islands. The Spaniards' stronghold was sporadically attacked. On 22 July 1883, it was reported that three unnamed men had succeeded in penetrating Jolo's town plaza and killed three Spaniards. The word “Ajuramentado” was coined by the Spanish colonel Juan Arolas after witnessing several such raids while serving with the Jolo garrison.