Manso de Velasco served as governor of Chile from November 1737 to June 1744, during which time he stood out for his numerous projects. His tenure saw the construction of the first public food market in Santiago, irrigation canals on the Maipo River as well as breakwaters on the Mapocho River, the rebuilding of Valdivia, and the celebration of an armistice with the indigenous Mapuche people, signed in the "Parlement of Tapihue". In addition, he founded a large number of Chilean cities listed here with their current names, their given names, and their date of founding:
His efficiency and diligence recommended him to a higher post, and Ferdinand VI named him viceroy of Peru in 1745, making him the first governor of Chile to be elevated in such a manner.
On October 28, 1746 at around 10:30 at night, a major earthquake struck Lima and vicinity, resulting in one of the highest number of deaths for such an event in the area. Witnesses differ on the duration of the event, with reports ranging from 3 to 6 minutes. The intensity of the quake is today estimated at X or XI on the Mercalli intensity scale. The aftershocks, by the hundreds, continued for the following two months. In Lima, the destruction was severe. Of 60,000 inhabitants, 1,141 were reported to have died. Only 25 houses remained standing. In Callao, a tsunami of nearly 17 meters in height penetrated up to 5 kilometers inland leaving only 200 survivors out of a population of 5,000. The fact that the earthquake struck at night probably contributed to the casualties, as many people were caught asleep in their homes. In the wake of the disaster, the population was gripped by hunger and fear. As a result of this earthquake, building practices were modified, with the adobe style abandoned for quincha construction techniques, which resulted in more flexible structures that were more resistant to disruptive seismic activity. On February 10, 1747 he founded the city of Bellavista. On May 30, 1755 the cathedral of Lima was begun.
Last days
The aged and tired Manso de Velasco asked for permission to return to Spain for his retirement, and received a positive answer from the crown in 1761. However, his trip home took him through the port of Havana in the then-Captaincy General of Cuba, just at a time when the colony was under siege. The British laid siege to the port, and Manso de Velasco, nominally the highest-ranking military officer in the area, found himself named the "Chief of the War Council" by the Governor of Cuba. Thus, at age 74, he led the defense of the fortified city. Unfortunately, the troops under his command were poorly trained and their equipment was inferior, leading to a Spanish surrender after only 67 days. at Conde de Superunda street in Priego de Córdoba dedicated to the homonymous count. Captured by the British, he was eventually brought to Cadiz in Spain. Due to his position as "Chief of the War Council", he was imprisoned in Madrid and tried by a court-martial presided over by the Count of Aranda. He and other accused chiefs were held responsible for the inglorious defeat in Cuba by this court-martial. Charles III, King of Spain, ratified the sentences on March 4, 1765 ending the process. The sentences were not lenient, Manso de Velasco was condemned to 10 years of exile to 40 leagues from the Court, seizure of goods and he was made jointly responsible for compensating harmed Habaneros. Shortly after being notified of the sentence Manso de Velasco left for his exile in Priego de Córdoba, where he arrived the same year. Less than two years later, on January 5, 1767, he died in the same city, where his remains still lay in the Church of San Pedro.
