but Alvarado accompanied Cortés on the inland march. While marching toward Tenochtitlan, the expedition made a slight detour to travel through Tlaxcalteca lands. The Tlaxcalteca attacked the Spanish force numerous times but they were unable to rout the Spanish forces. After making an alliance with the Tlaxcalteca, the Spanish went on to conquer the Aztecs. Alvarado commanded one of the eleven vessels in the fleet and also acted as Cortés' second in command during the expedition's first stay in the Aztec capital city of Tenochtitlán. Relations between the Spaniards and their hosts were uneasy, especially given Cortés' repeated insistence that the Aztecs desist from idol worship and human sacrifice; in order to ensure their own safety, the Spaniards took the Aztec king Moctezuma hostage. When Cortés returned to the Gulf coast to deal with the newly arrived hostile expedition of Pánfilo de Narváez, Alvarado remained in Tenochtitlan as commander of the Spanish enclave, with strict orders to make sure that Moctezuma not be permitted to escape. During Cortés' absence, relations between the Spaniards and their hosts went from bad to worse, and Alvarado led a massacre of Aztec nobles and priests observing a religious festival. Alvarado claims he did so because he feared the Aztecs were plotting against him but there is no physical evidence to support this claim and the alleged warnings he received came from tortured captives that very likely would have said anything to make the torture stop. When Cortés returned to Tenochtitlan, he found the Spanish force under siege. After Moctezuma was killed in the attempt to negotiate with his own people, the Spaniards determined to escape by fighting their way across one of the causeways that led from the city across the lake and to the mainland. In a bloody nocturnal action of 10 July 1520, known as La Noche Triste, Alvarado led the rear-guard and was badly wounded. According to satirical verses by Gonzalo Ocampo, in reference to Alvarado crossing a causeway gap during the escape, Alvarado's escape became known as Salto de Alvarado ("Alvarado's Leap"). Pedro then participated in the Siege of Tenochtitlan, commanding one of four forces under Cortés. Alvarado was wounded when Cuauhtemoc attacked all three Spanish camps on the feast day of St. John. Alvarado's company was the first to make it to the Tlateloco marketplace, setting fire to the Aztec shrines. Cortés' and Sandoval's companies joined him there after