Morgan, as unwilling as the rest to revisit Port Royal empty-handed, proposed a new expedition, in search of a greater prize. But the French, not able to agree with the English, left the fleet, in spite of all their commander's persuasions, but still with every external mark of friendship, entreating to the last to have justice done to the "infame."
Morgan, who had always placed great reliance on the courage of the French adventurers, was not going to relinquish his new expedition on account of their desertion. He had inspired his men with courage and the hope of acquiring riches, and they all resolved to follow him to the attack of the place, whose name he would not yet disclose, exciting them by a mystery, which prevented the possibility of treachery.
He put forth to sea with eight small vessels, but was soon joined by an adventurer of Jamaica, just returning from Campeachy; with this new ally, he had now a force of nine vessels and 470 men, many French being still among them, and arrived at Costa Rica with all his fleet safe.
As soon as they sighted land, he disclosed his design to his captains, and soon after to all his seamen. He intended to storm Porto Bello by night, and to put the whole city to the sack: he was confident of success, because no one knew of his secret; although some of his men thought their force too small for such an enterprise. To these Morgan replied, that if their number was small, their courage was great, and the fewer they were the more booty for each, with the greater prospect of union and secresy; and upon this, all agreed unanimously to the design.
By good fortune, or by preconcerted arrangement, one of Morgan's crew turned out to be an Englishman who, only a short time before, had been a prisoner at Porto Bello, and his past sufferings now proved to have been the foundation of his future good fortune. Having escaped from that place, he knew every inch of the coast, which had been so painfully impressed on his mind, and Morgan submitted, with perfect confidence, to his guidance. By his advice, they steered straight for the bay of Santa Maria, arriving there purposely about dusk, and reached a spot about twelve leagues from the city, without meeting any vessel. They then sailed up the river to Puerto Pontin, four leagues distant, taking advantage of the land wind that sprang up, cool and fresh, at night.
They here anchored, and embarked in boats, leaving a few men to bring on the ships. Rowing softly, they reached about midnight a place called Estera de Longa lemos, where they all landed, and marched upon the outposts of the city.
Michael Scott describes Porto Bello as built in a miserable, dirty, damp hole, surrounded by high forest-clad hills, wreathed in mist, and reeking with dirt and fever. Everlasting vapours obscure the sun, and mingle with the exhalation of the steaming marshes of the lead-coloured, land-locked cove that forms the harbour.
They were now within reach of the strongest city in the Spanish West Indies, except Havannah and Carthagena, the port of Panama, and the great mart for silver and negroes. Leaving as usual a party to guard the boats, and preceded by their guide, they began halfway to the town to prepare their arms. Upon approaching the first sentinel, Morgan sent forward the guide and three or four others to surprise him. They did it cunningly, before he could fire his musket, and brought him with his hands bound to Morgan, who, threatening him with death, asked him how things in the city went, and what forces they had, making a "thousand menaces to kill him if he did not speak the truth." The terrified Spaniard informed them that the town was well garrisoned, but that there were very few inhabitants; the merchants only residing in the town while the galleons are loading, and that he would be able to take the place in spite of all the fortresses and the 300 soldiers. Morgan then pushed on to the fort, carrying the man bound before them, and after a quarter of a league reached the castle, where the man's company was stationed, closely surrounding it, so that no one could get in or go out. The prisoner had in vain attempted to avoid this redoubt, to which he had served as picket, encouraged by Morgan's promises of reward, and avowal that he would not give him up to his countrymen.
The Spaniards, finding the sentinel gone, had already spread the alarm of the Buccaneers' approach. From beneath the walls Morgan commanded the sentinel to summon the garrison to surrender at once to his discretion, or they should be cut in pieces without quarter. Not regarding these threats, the Spaniards began instantly to discharge their guns and muskets to alarm the town and obtain succour. But though they made a good resistance they were soon overpowered, and the Buccaneers, driving them into one room, set fire to the powder which lay about on the floor, and blew the tower and its defenders together into the air; all the survivors they put to the sword, in order to strike terror in the city.
At daybreak they fell upon the city, and found the inhabitants, some still asleep and others scared and alarmed; many had thought of nothing but hiding their treasure, and only the professional soldier prepared for resistance. The governor, unable to rally the citizens, fled into the citadel, and fired upon the town as well as the enemy. The frightened herd, stupid with fear, were throwing their money and jewels into wells and cisterns, or burying their treasure in their courtyards, cellars, gardens, and chapels. The adventurers, abstaining from pillage, sent a chosen party to the convents to make prisoners of the religious, male and female; while another division prepared ladders to escalade the fort, not relaxing for a moment either in attack or defence. They attempted in vain to burn down a castle-gate which proved to be of iron, and baffled their efforts, and kept up a warm fire at the embrasures, aiming with such dexterity at the mouths of the guns as to kill a gunner or two every time the pieces were either run out or loaded.