Straits of Gibraltar

The Straits of Gibraltar appear as a dangerous passage in the maritime world John Blackthorne knows from experience: a route he sailed while piloting for the London Company of Barbary Merchants, watched by Spanish patrols and embedded in a Mediterranean crowded with hostile naval powers.

Setting and Maritime Context

Blackthorne’s routes carried him from the waters of West and North Africa, south as far as Lagos, then north and east through the Straits of Gibraltar to Salerno in the Kingdom of Naples. The passage is characterized less by description of its landscape than by its strategic exposure: it was patrolled by Spain, while the Mediterranean as a whole was dangerous for English and Dutch shipping. Spanish and Portuguese forces were present in strength, alongside Ottoman ships and slave galleys.

Blackthorne’s Experience

For ten years, Blackthorne served as a pilot and ship’s master for the London Company of Barbary Merchants, which equipped armed merchantmen to evade the Spanish blockade and trade along the Barbary Coast. His passage through the straits belongs to a career built on navigating contested waters. After those voyages proved profitable, he bought a 150-ton brig to trade independently; it was later lost to a Turkish galley off Sardinia. That attack occurred elsewhere in the Mediterranean, but it underscores the hazards of the maritime environment in which the straits were one of his routes.

Navigation and Strategic Significance

The passage also sits within a world where safe navigation depended on scarce, imperfect information. Charts could be too vague to guide a voyage reliably, and longitude could not be fixed. Pilots therefore relied on rutters: working books recording courses between ports and capes, soundings, water and seabed conditions, winds, currents, storms, havens, and dangers. Such guides could contain errors, even deliberate ones, so a pilot’s judgment and firsthand experience remained essential. The Straits of Gibraltar’s significance in the account is consequently both geographic and practical: they formed part of a working route through waters where knowledge, patrols, and armed ships determined the risks of passage.