William Miller was already in the fight when his reinforcements arrived. On the morning of February 18, 1820, the Englishman-turned-patriot soldier led sixty men up a narrow, broken road on Chiloé's northern tip, charging the Spanish guns of the San Miguel de Agüi fort. Musket fire poured from the walls. Within minutes, thirty-eight of his men lay disabled in the scrub, and Miller himself had taken a ball in the leg. He would have to be carried back to the boats. The last Spanish stronghold in Chile had just repelled its first attack.
By 1820, Spain's grip on Chile had nearly slipped. Lord Cochrane, the audacious Scottish admiral commanding the young Chilean navy, had just seized the fortress city of Valdivia in a night assault that stunned the continent. Only one prize remained: the Chiloé Archipelago, a fog-laced cluster of islands at the foot of the mainland where royalist governor Antonio Quintanilla still held out. Cochrane meant to finish the job. He landed Major Miller and a small force on the Lacuy Peninsula near Ancud, where the Spanish had fortified the heights above the water. Take Agüi, the thinking went, and Chiloé would follow. The thinking was wrong.
The terrain favored the defenders absolutely. The approach to the fort ran along a single rough track, too narrow for a broad advance, hemmed in by rock and forest. When Spanish commander Saturino García rushed to reinforce the garrison, Miller sensed the window closing and ordered the charge before it could shut. Sixty men went up that road. Cannon and musket fire raked them from the walls above. Thirty-eight fell, Miller among them, his leg shattered. Command passed to Captain Francisco Eréscano, who reformed the survivors into a fresh column and tried again. The walls would not break.
Just as Eréscano pressed his attack, the situation turned worse. Governor Quintanilla had dispatched a gunboat from San Carlos, and now it came around to rake the patriot column from the side. Caught between the fort's guns ahead and naval fire on the flank, the Chileans could not hold. Eréscano made the hard, disciplined choice. Rather than break and run, he pulled his men back in order, evacuating the wounded and screening his rear from the garrison García was steadily reinforcing. Three times the Spanish surged out to attack the retreating column. Three times they were repelled.
The retreat ended on the sand. The patriot column marched down Huechucucuy Beach to the cove where their ships lay anchored, carrying their wounded with them. At the shoreline the Spanish pursuit simply stopped, perhaps fearing that the small landing party was the advance guard of something larger waiting offshore. Miller survived his wound and went on to a long career, eventually a general in Peru. But Agüi had proven the obvious: Chiloé would not be taken by a single bold rush. The archipelago held out until 1826, the very last patch of South American soil where the Spanish flag still flew, falling only six years after this brief, bloody morning above the beach.
The Battle of Agüi was fought on the Lacuy Peninsula at the northern tip of Chiloé Island, at approximately 41.83°S, 73.86°W, near the city of Ancud. From the air, look for the peninsula's wooded heights overlooking the entrance to the Chacao Channel, with Huechucucuy Beach along the shore below. The nearest major airport is Aeropuerto El Tepual (SCTE) at Puerto Montt, about 50 nm northeast; the regional Mocopulli Airport (SCPQ) near Castro serves Chiloé itself. The Gulf of Ancud and the Chacao Channel are frequently cloud-covered; clear viewing is best in summer (December–February). Recommended viewing altitude is 3,000–5,000 feet for the coastal fortification heights.