Task: Question Answering
Input (English): Passage: Writing after the fall of Nojpetén, friar Cano described the ultimate fate of Díaz de Velasco and his companions; he claimed to have received the information from interviews with the soldiers from Yucatán who had stormed the Itza capital and from Chʼol witnesses, although there were no Chʼol at Nojpetén. Díaz's party arrived at the lakeshore and were told by local Itza that Franciscan friars were at Nojpetén. They were wary at first and asked for proof, upon which an Itza messenger brought them a rosary as a token. Looking across the lake they saw men dressed as friars calling to them to come across, these were Itza dressed in the habits of the two Franciscans who had recently been killed at the island. Díaz and his companions then boarded the Itza canoes, leaving thirty Maya porters with their mules and supplies.Once on the lake the Itza overturned some of the canoes and killed some of Díaz's men; others were wounded and dragged ashore to be killed. Díaz, the Dominicans and two other men were in a large canoe that was not overturned and were taken to Nojpetén where a fierce struggle ensued as Díaz attempted to defend himself with his sword, killing several Itzas. The two other men were immediately killed while the friars were beaten and tied to X-shaped crosses before having their hearts cut out. Across the lake, the Itza attacked the porters guarding the expedition supplies and killed all of them. The Itza killed a total of 87 expedition members, including 50 soldiers, two Dominicans and about 35 Maya helpers. The remains of the small group that were killed on Nojpetén were later retrieved by the Spanish after the fall of the city and were taken back to Santiago de los Caballeros de Guatemala for burial. 
Question: What is the first name of the leader of the party that were wary at first and asked for proof?
Output (English): Díaz.