How Vernon's fleet captured Portobelo in 1739

Portobelo was an important staging point for the Spanish treasure system and had forts and troops even in peacetime, but its defences were not ready when Vernon arrived on 20 November 1739. An easterly wind forced the British ships toward the harbour fort described as the Iron Castle. Sailors and Royal Marines landed, scaled its walls, lowered the Spanish colours, and raised the Royal Navy ensign. Although the fort supposedly had a 300-man garrison, only about 40 troops remained when it surrendered; the attackers then moved against Santiago Fortress and sank a Spanish sloop. The governor sought terms by the following day, and the British occupied Portobelo for three weeks while destroying its value as a maritime base. They took three prizes, including a snow renamed Triumph and two coastguard vessels, at a cost of three killed and seven wounded in the account presented here.