From the 17th to the late 18th century a series of parliaments were held between royal governors and Mapuche lonkos and the war devolved to sporadic pillaging carried out by both sides.

In the words of Philip II, this conflict cost the largest number of Spanish lives in the New World, which is why it became known as the Flandes indiano ("Indian Flanders"), in reference to the Eighty Years' War.

The Spanish designs for this region was to exploit the placer deposits of gold using Mapuche (slave) labor from the densely populated nearby valleys.

[8] Lacking a tradition of forced labor like the Andean mita, the Mapuches largely refused to serve the Spanish, setting the stage for the conflict.

[14] An antecedent of the Arauco War was the Battle of Reynogüelén, which occurred in 1536 between a detachment of Diego de Almagro's expedition and a large group of Mapuches, near the confluence of the Ñuble and Itata rivers.

Recently arrived Pedro de Valdivia in central Chile is confronted by the toqui Michimalonco, who a couple of years before had expelled the Incas from the northern Mapuche controlled territory (and with Picunche presence).

The resounding victory leaves Pedro de Valdivia confident, who decides to found the city of Santiago in the Mapocho valley and begin organizing the nascent colony.

Trangolonco addresses as ambassador to all the indigenous chiefs of the Cachapoal, Maipo and Mapocho valleys to send their contingents and join Michimalonco, so that, just as he did with the Incas, he expels the Spanish from the Wallmapu.

In 1544, a naval expedition was sent, comprising the barks, San Pedro and Santiaguillo, under the command of Juan Bautista Pastene, to reconnoiter the southwestern coast of South America to the Strait of Magellan.

The expedition set sail from Valparaíso, entered the bay of San Pedro, and made landings at what is now known as Concepción and at Valdivia, which was later named in honor of the commander.

After spending over a week in the area and encountering increasing opposition, the Spanish marched toward the sea through the valleys of the Laja and Bío-Bío rivers, towards the coast at Penco.

After garrisoning these new places, Valdivia returned to his base at Concepción in 1552 where rich placer gold mines were found in the Quilacoya River valley.

[18] After the defeat at Tucapel, the Spanish hurriedly reorganized their forces, reinforcing fort Imperial for its defence and abandoning Confines and Arauco in order to strengthen Concepción.

It was only in February 1554 that he succeeded in putting together an army of 8,000 men, just in time to confront a punitive expedition under the command of Francisco de Villagra at the Battle of Marihueñu.

In Santiago, Villagra reorganized his forces, and that same year of 1554, he departed again for Arauco and reinforced the strongholds of Imperial and Valdivia, which allowed the garrisons and their Indian friends to make many raids on the surrounding Mapuche settlements, burning houses and fields and killing all they found.

But when he entered the places subject to Santiago, he began taking reprisals against the Promaucaes who refused to join him, doing great damage and depopulating the land.

Captain Gudiñez returned victorious from this pursuit and put great fear into the Promaucaes by punishing them with destruction of their herds, fields, and houses and by cutting off some heads, as a lesson not to call upon the Mapuche army or give aid to them.

On April 29, at dawn Villagra began the Battle of Mataquito with a surprise attack on the camp in which they killed Lautaro and obtained a decisive victory, destroying his army and dispersing his allies.

After further fighting near the site of the ruined fortress of Tucapel, Mendoza built the fort and city of Cañete de la Frontera and continued to the south.

Attempting to throw off the Spanish occupation, Caupolicán attacked the fort of Cañete expecting the gates to be opened by the treachery of a yanakuna within, but he was betrayed instead and was badly defeated by Captain Alonso de Reinoso.

After the battle, Hurtado de Mendoza had most of the captured Mapuche executed, but saved Peteguelén, son of Cuyomanque, an important cacique in the Arauco region.

This success was due to the large numbers of experienced soldiers, equipment, and arms that he brought which were not available to the previous conquerors and because the Mapuche did not have a strategist to equal Lautaro.

Because he believed he had too few men to hold all the posts in Mapuche territory and still have a field army, the new governor Pedro de Villagra ordered the abandonment of Arauco in July 1563, taking off its artillery and noncombatants by sea while the garrison under Lorenzo Bernal del Mercado marched over the rain soaked mountains and flooded rivers to Angol.

In addition, Millalelmo ambushed Spanish reinforcements coming from Angol to the south under captain Juan Perez de Zurita, at a crossing of the Andalién River.

He accomplished the conquest of the island of Chiloé, sending Martín Ruiz de Gamboa to establish the city of Castro there, and pacify its inhabitants, the Cuncos.

In September 1567, the king named Melchor Bravo de Saravia y Sotomayor to take over the civil and military government of Chile, with the title of governor and he arrived from Lima in 1568.

Governor Melchor Bravo de Saravia y Sotomayor arrived from Lima in 1568 and recruited 100 new soldiers and gathered food in Santiago province and marched south to join the army near the mouth of the Tavolevo River in Catirai.

Despite his early successful campaign when he captured Alonso Diaz in 1584, he wanted to extend the conquest of Chile by building a series of forts which would protect each other, the cities, and their surrounding lands.

Opposing these moves by Sotomayor was the Toqui Cayancaru who attempted a siege of the fort at Arauco that failed, leading to his abdication of his office in favour of his son Nangoniel in 1585.

The Disaster of Curalaba became the beginning of a general uprising that resulted in a six-year struggle called the Destruction of the Seven Cities that eliminated all Spanish settlements south of the Bio-Bio River with the exception of those in Chiloé Archipelago.