Each year the City of La Paz, Baja California Sur, celebrates its founding by the famous (or infamous) explorer Hernan Cortez on May 3, 1535. But La Paz hasn't always been the capital of Baja California Sur, nor has it been consistently inhabited over its more than 485-year history.

In 1534 Hernan Cortez returned to New Spain (mainland Mexico) and began to organize a third expedition to the west. Like much of the conquest of the region by the Spanish, it was driven by the quest for land, gold, and souls to save. 

Unfortunately, his nemesis, Nuño de Guzmán, had seized two of Cortez's ships. Guzmán was governor of the province of New Galicia, so Cortez assembled a sizable force of equestrians and foot troops and prepared to march on New Galacia to recover his ships and launch his third west coast expedition from there. 

The Viceroy of New Spain, Don Antonio de Mendoza, warned Hernán Cortés "not to confront whoever had requisitioned his ships." The plea fell on deaf ears for Hernán Cortés, as he alleged that he had spent more than 100,000 Castilians in gold on the two vessels and the expedition, besides having been designated by his Majesty the King of Spain Felipe II to conquer and discover new territories. 

But the feared confrontation between the forces of Cortés and Nuño de Guzmán never came to pass, as Nuño de Guzmán learned of Cortés' approach and knew his reputation and backed down, returning the vessels. 

In Chametla territory of the New Galicia province, now Sinaloa, Cortés and his forces boarded the ships "Santa Águeda" and "San Lázaro" According to documents from the royal governor Guzman the party included 113 footsoldiers, 40 riders on horseback. He left another 60 horsemen and supplies in Sinaloa to resupply the expedition once it established itself on the western side of the Sea.

Cortés' flagship was the San Lázaro, and from it, they plotted a course to the northwest. On May 3, 1535, he arrived in a tranquil bay, named it Bahia Santa Cruz, and claimed it for the King of Spain. His log also notes that on the first contact with local natives, his subordinate, Fortún Jiménez, was killed. 

Cortez founded a colony in the southernmost portion of Bahia Santa Cruz, now known as the Bay of La Paz. The original settlement was located near the freshwater source along the northeastern end of the Malecon and where the Molina (windmill) is located today. 

But the settlement could have done better, and the resupply portion of the expedition suffered heavy losses in the crossing from the mainland to the territory. After only meager supplies reached the settlers, the Viceroy ordered Cortez and his expedition back to New Spain. 

In 1540, Cortés retired to Spain. He spent much of his later years seeking recognition for his achievements and support from the Spanish royal court. Cortés died in Spain in 1547.

Years later, Admiral Sebastian Vizcaino baptized the settlement in 1596 as La Paz.

In 1683 Admiral Isidro de Atondo y Antillón took possession of the port settlement and designated it as Puerto de Nuestra Señora de La Paz on behalf of Carlos II of Spain. 

In 1720 the Mission of La Paz was founded by the Jesuit fathers Juan de Ugarte and Jaime Bravo. 

In 1616 the Dutch pirates, nicknamed "Los Pichilingues", anchored their ships, "Gran Sol" and "Luna Llena", in a bay near La Paz that is now named after them and is the commercial port for the city and most of the southern peninsula.

The capital of the Californias was transferred to La Paz in 1830

The settlement was re-established several years later and renamed La Paz. The original capital of the territory was Loreto, which was founded 162 years later and continuously inhabited. The years followed, and the La Paz settlement was abandoned a couple more times for disease, lack of water, and famine. So there is some contention as to which is the oldest city on the peninsula. (https://en.wikipedia.org/wiki/Nueva_Galicia)