Bernardo de Gálvez, the energetic governor of Spanish Louisiana, had immediately begun offensive operations when Spain entered the American Revolutionary War in 1779.

In September 1779 he had gained complete control over the lower Mississippi River by capturing Fort Bute, then shortly thereafter obtaining the surrender of the remaining British forces on the river following the Battle of Baton Rouge.

Following these successes, he began planning operations against Mobile and Pensacola, the remaining British presence in the province of West Florida.

Gálvez has assembled a mixed force of Spanish regulars and militia in New Orleans.

He had requested additional troops from Havana for operations against Mobile and Pensacola in 1779, but his requests had been rejected.

Before departing New Orleans, he dispatches one of his lieutenants to Havana to make one last request.

A fleet of twelve ships carrying seven hundred and fifty-four men had set sail on January 11, 1780, reaching the mouth of the Mississippi on January 18.

They are joined on January 20 by the Gálveztown (brig sloop), under the command of Captain William Pickles and with a crew of fifty-eight.

A storm had scattered the fleet on February 6, but all ships had arrived outside Mobile Bay by February 9.

The fleet had encountered significant problems actually getting into the bay.

Several ships had run aground on sand bars, and at least one, the Volante, had been wrecked as a result.

Gálvez had salvaged guns from the wreck and set them up on Mobile Point to guard the bay entrance.

On February 20, reinforcements had arrived from Havana, bringing the force to about twelve hundred men.

By February 25, the Spanish had landed their army on the shores of the Dog River, about ten miles (sixteen kilometers) from Fort Charlotte.

They are informed by a deserter that the fort is garrisoned by three hundred men.

Fort Charlotte was built in 1717 by the French as Fort Condé when Mobile was part of the French province of Louisiana (New France).

By 1763, when the British took over following the French and Indian War, the fort was in ruins.

While it was repaired at that time, by the time hostilities with Spain neared in 1779, it was again in disrepair.

The garrison's regulars are primarily from the 60th regiment, and are augmented by Loyalists from Maryland and Pennsylvania, as well as local volunteers, in total about three hundred men.

Ever since news of Gálvez' successes had reached Mobile, Elias Durnford, who had taken command of Fort Charlotte in January 1780, had been directing improvements to the fort's defenses.

On March 1, Gálvez had sent Lt. Col. Francisco Bouligny to deliver a letter to Durnford offering to accept his surrender, which was politely rejected.

Gálvez began setting up gun batteries around the fort the next day.

Durnford wrote to General John Campbell at Pensacola requesting reinforcements.

On March 5 and 6, most of the Pensacola garrison left on a march toward Mobile.

Delayed by difficult river crossings, this force will be unable to assist the Fort Charlotte garrison.

While the Spanish engaged in siege operations to move their guns nearer the fort, Gálvez and Durnford had engaged in a courteous written dialogue.

For example, Gálvez had politely criticized Durnford for burning some houses in order to deny the cover they provided to the Spaniards.

Durnford had responded by pointing out that the other side of the fort (away from most of the town) offered a better vantage point for attack.

All the while, the Spanish had continued to dig trenches and bombard the fort

On March 13, the walls of Fort Charlotte were breached, and Durnford capitulates the next day, surrendering his garrison.

Gálvez had not immediately moved against Pensacola after his victory at Fort Charlotte, although he wants to take advantage of the British disorganization caused by the attempt to support Mobile.

However, since he knows that Pensacola is strongly defended, and armed with powerful cannons, he again requests large-scale naval support from Havana.

He learns in April that additional reinforcements, including British Royal Navy vessels, have arrived at Pensacola.

Without Spanish reinforcements, he leaves a garrison in Mobile, and departs for Havana to raise the troops and equipment needed for an attack on Pensacola.