Antón Mayor formally took possession of the territory in the name of the Spanish crown, the first Spanish act in the territory of what is now Nicaragua. They met no opposition at that time, and the act was officially recorded by Juan de Almanza, who acted as scribe for the legal documentation. To commemorate this act, they named the place Posesión. Niño sailed onwards, making landfall on an island in the Gulf of Fonseca on 5 March, giving the gulf its name in honour of Spanish bishop Juan Rodríguez de Fonseca. Niño continued onwards as far as the Isthmus of Tehuantepec, in what is now Mexico. Expedition inland Meanwhile, on his march inland, Gil González heard rumours of a powerful native ruler called Nicarao, who commanded many warriors. He was advised not to continue, but decided to march on until he met opposition. Nicarao intercepted Gil González outside his capital city, called Quauhcapolca, and received him in peace. He invited the Spaniards to lodge near the city plaza and the two leaders exchanged gifts; González wrote that he received the equivalent of 15,000 gold castellanos. The Spanish captain gifted Nicarao with silk clothing and many other items brought from Spain. Over the course of the next few days, the Spanish instructed the natives in the basics of Christian religion. He claimed that after this, the natives wished to convert to the new religion, and that just over 9,000 people were baptised in one day, including adults and children of both genders. After several days in the Nicarao capital, González learned of Lake Nicaragua, and he sent a small detachment of soldiers to confirm its existence; he then travelled in person with 15 foot soldiers and 3 mounted soldiers. Among those who went with him to the lakeshore were the expedition's treasurer Andrés de Cereceda, and friar Diego de Agüero. On 12 April 1523 they claimed the lake for the Spanish Crown under the name of Mar Dulce ("sweet sea"). González sent out a canoe to scout the lake for a short distance, and questioned the natives as to whether it connected with the sea, without receiving any clear response; nonetheless, the Spanish were convinced that the lake must have an outlet to the Caribbean Sea, and that they had discovered a new route across the Central American isthmus. A great many natives came to see the newly arrived Europeans, driven