Castillo de San Marcos

and Fort Matanzas

     The Spanish treasure and trade network included exotic goods from the Far East funneled through the Philippines to Mexico.  These goods and Peruvian silver were transported across Mexico and sent to Havana along with Mexican silver for an annual voyage to Spain, a voyage vital to Spanish government and always eagerly awaited.  The treasure route from Havana to Spain used the Gulf Stream along the coasts of Florida and North America.  In 1564 the French settled Florida at Fort Caroline near modern day Jacksonville, a clear threat to the Spanish treasure ships.  In response, the Spaniards settled at St. Augustine and slaughtered the French settlers.  For over a century, wooden forts protected the town of St. Augustine.  The settlement survived a burning in 1586 by Francis Drake as well as a pirate attack in 1668.  This and the extension of British settlement to Charleston convinced the Spanish to build a permanent stone fort at St Augustine - Castillo de San Marcos.

     Castillo de San Marcos was completed in 1695.  In 1702 during the War of Spanish Succession, British colonials occupied the town of St. Augustine but failed to take the fort.  In 1740, the town resisted another British/colonial siege.  In response to a potential enemy riverine advance from the south, Fort Matanzas was built in 1742.  During the Seven Years War, British troops took Havana, the key to the Spanish empire.  The peace treaty gave Florida to Britain in exchange for the return of Havana.  At the conclusion of the American Revolution, Florida was returned to Spain, and in 1821 the United States gained control of Florida.

From the Southwest Corner

     Typical of smaller European styles and in keeping with a design dating to the early 16th century, the square fort has diamond shaped bastions at each corner to enfilade any attack on the walls, called curtains.  The outwork on the right side of the picture is the ravelin or demi-lune.  It protects the gate into the fort, which is on the town side.  A fort guarding an important European city would have more sides, or curtains, and more outworks, but the basic concepts would be the same.  (For extensive material on European forts, see  John's Military History Tour of Europe.)  Cannon mounted the walls which were protected by a ditch, which could be wet or dry.  The covered way is the grassy area outside the ditch.  Infantry could occupy this area behind the cover of the low stone wall.  Beyond this, the gently sloping glacis gave the defenders a clear field of fire.  On the left, the Cubo Line, the city walls of St Augustine, extend west to the river.  This type of fort was an evolution of forts originally designed in the late 1400s to protect against the new mobile artillery which could easily destroy tall, narrow medieval walls.

Northwest Corner

An enemy approaching from the north would face the northern side of the fort, liking digging approach trenches.  In the distance, a channel opens to the Atlantic.

Northeast Bastion

This view shows the landward face as well as the bay and its entrance.  Anastasia Island is on the right.  In 1740, Ogelthorpe's British force bombarded the fort from there until they withdrew after failing to take the fort.


Being dutiful citizens, we pay a parking fee and an entrance fee to a fiscally responsible government, then cross a bridge followed by a drawbridge to enter the ravelin.  By design, to enter the fort you were vulnerable to enemy fire and had to pass at least two checkpoints.

The Ravelin 

Construction of the ravelin was never completed.

Next, we proceed across the bridge toward the drawbridge and the gate.

The 360 degree view above has some distortion, making straight lines curved, but it gives an excellent overview of the fort.  Ahead of us, across the drawbridge, the gate includes a sliding portcullis.

Ravelin From Above

And from above we can see that the ravelin is lower.  If an attacker succeeded in capturing it, fire from the curtain wall would make it difficult to hold.

Cubo Line

After the British captured the town in 1702, the Cubo Line was constructed to better protect Saint Augustine.  This line was made of palm logs and dirt and was fronted by a ditch.

The Castillo served as a citadel, the final refuge for defenders of the town, as well as a point from which government authorities could dominate the town and its residents, if necessary.

Northeast Bastion

This is the northeast bastion.  At the very corner was a guardhouse, or sentry post, constantly manned to detect intruders on land or sea.  Visible below at left is a shot furnace.  In the 1840s, the US Army replaced the ditch on this side with a seawall with artillery mounted.  A shot furnace could be used to heat shot for use against wooden warships.


Surrounding the inside are a series of casemates built as a later addition in the 1730s.  With mortars a valuable siege weapon, casemates provided overhead protection.  The design also allowed for bigger guns above.

Casemates Near the Entrance

The fort's entrance is through the passage at left.

Although difficult to show because of close quarters, during the British period, men would live on two levels within casemates.


North of St Augustine was another fortification, Fort Mose, manned by soldiers who had escaped slavery in the English colonies to the north and accepted Catholicism.  Fort Mose was captured and destroyed by the English in the 1740 attack, but the Spanish rebuilt afterwards and even extended a trench for two miles to the San Sebastian River to the west.  About 20 miles west of St Augustine along the St Johns River there were two other forts - Picolata and Pupo.  These two forts, and the original Fort Mose, were blockhouses.  Another post, Fort Diego, was a fortified home of a mulatto rancher about 20 miles north of St Augustine.   Together, these forts served to give advanced warning of enemy attack.

From the mid 1600s to the early 1700s, Spanish Florida was also defended by Indian client states that were aided by Spanish missionaries and soldiers.  Mission San Luis near modern Tallahassee is an excellent example.  Facing internal problems and English raids, however, the mission system fell apart.

Fort Matanzas:

South of St Augustine, the Matanzas River or Inlet leads north to the town.  In the early 1500s, survivors of the French Fort Caroline settlement had been massacred here by the Spanish, giving the area its name.  By 1569, the Spanish had built a wooden watchtower to give warning of enemy approach, but after the British use of the inlet in the 1740 attack, the Spanish decided that a stone fort was in order for the area.  The result is unique to what is now the United States.  Completed in 1742, it was built of coquina shellstone on wooden pilings  by soldiers, convicts, and slaves.  The structure is approximately 30 feet tall and measures 30 by 50 feet.  Rain water was collected in a cistern for drinking by the garrison that typically consisted of one officer and six men who rotated to and from St Augustine.  In 1742, the fort drove off a probe of several British boats.


The gundeck included a sentrybox and five cannon.  At the time the inlet opened into the Atlantic just half a mile away.  The door just to the right of the stairs leads to the soldiers' quarters.  The stairs lead to the officer's quarters where a ladder allows access tot he observation deck.

Soldiers' Quarters

Officer's Quarters

At right is access to the powder magazine.  The ladder leads to the observation deck.


Observation Deck

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