This was the great age of the filibusters, private armies, mostly originating in America, bent on liberating various New World portions of the Spanish Empire. One of the most far-reaching of these campaigns was the Gutierrez-Magee expedition, led by Bernardo Gutierrez and Augustus Magee.

Magee was a career soldier who had graduated third in his class from West Point. For a time he served in an artillery regiment stationed at Baton Rouge. Later, he transferred to Fort Jessup near Natchitoches.

About 1811, Magee had a quarrel with a Frenchman, and a duel with swords was the result. Judge William Murray acted as Magee's second. In the course of the duel, Magee had his little finger cut off, but, at the same time, he cut the Frenchman down with a heavy blow of his sword.

Ostensibly smarting after being rejected for promotion, Magee resigned his commission with the commencement of the War of 1812. In truth, he and Gutierrez had been organizing their forces for some time. The "Army of the North" left Natchitoches and marched under their solid green flag into Texas on August 2, 1812. The force initially received little opposition, easily occupying Nacogdoches, a garrison on the Trinity River, and La Bahía, before Spanish forces could act.

Although Magee, himself, had died by now from an illness, the invaders easily pushed the Royalist forces to the area around San Antonio de Bexar. The general engagement occurred on March 2, 1813. The invaders gave an order to their forces that, at the tap of the drum, a general charge should be made. Not understanding the order, Native American forces within the expedition charged sooner than they should. They suffered great casualties, losing some of their principal men in a hand-to-hand fighting; but they succeeded in killing a large number of Royalists.

The invaders made a general charge. In fifteen or twenty minutes the Royalists were routed and fled the field, in spite of every effort of their officers to rally them, leaving 330 men dead on the field, and 60 taken prisoners. The Spanish officers, some seeing they could not rally their men, rushed forward, sword in hand, determined to sell their lives as dearly as possible in single combat. In consequence, a disproportionate number of officers were found among the dead.

When the Spanish commander saw the day was lost, he turned his horse toward the American line, and rushed into their ranks. He first attacked Major Ross, and then Colonel Kemper. As his sword was raised to strike the latter, he was shot dead by one William Owen, a private in Captain Joseph Taylor's company.

The expedition next defeated a Royalist army of 1,200, under General Herrera, in the battle of Rosillo. In a letter sent a little later, John Sibley wrote, "On the 29th was met about Eight Miles from St. Antonio by General Herrera with Twelve hundred Men & Six Pieces of Cannon, a Battle Ensued which Continued about an hour. Good part of the time with Bayonets & Swords in hand the two Armies all Mingled together the Result was Herrera was Compleatly defeated."

The invaders marched to the borders of San Antonio and sent in a flag, demanding the surrender of the place and garrison. Governor Salcedo asked till morning to make his arrangements for the capitulation of the place. A second flag was sent in, notifying him that, if he and his staff did not immediately proceed to the filibuster camp, with the flag, they would storm the town. Salcedo with his staff, fourteen in all, complied with this demand. He surrendered San Antonio unconditionally on April 1.

The governor approached Captain Taylor, and presented him his sword. Taylor referred him to Colonel Kemper. Kemper declined to receive it, but referred him in turn to Bernardo Gutierrez. It was too much. Salcedo stuck his sword into the ground in front of Gutierrez and left it there.

Gutierrez took it up.

The Spanish troops, stores, and arms were all surrendered. The filibusters entered the Alamo, releasing seventeen of their countrymen whom they found imprisoned there and placed them in the ranks of the "Republican Army of the North." The Spanish soldiers taken as prisoners were set at liberty. Some joined the ranks of the republicans, and the rest repaired to their homes. Salcedo and his staff were permitted the liberties of the town on their parole of honor

Gutiérrez began to assume a greater role in the expedition's affairs. On April 3 Gutiérrez directed that the captured Governor and the officers of his staff, who did not join the revolution, be sent under escort to La Bahía where they could be better secured. Kemper agreed. Soon after, the governor and his party left Béxar, they were bound hand and foot by their escorts, led by Captain Antonio Delgado, and, as Texas historian and author Ted Schwarz reports from depositions taken from Mexican Royalist soldiers, "The prisoners were dismounted, disrobed, and robbed of their valuables. Governor Salcedo's tongue was cut out. After being refused spiritual sacrament, they were beheaded with swords whetted on the soles of their executioners' boots. The bodies were left on the field unburied."

The murders were quickly discovered and the American contingent was horrified by the wanton killing. Particularly appalling to the Anglos was the fact that the prisoners had been guaranteed protection under their word of honor. Desertions began almost immediately and several took "furloughs" back to American territory.

The Royalist forces returned with a vengeance. With a small army, badly demoralized by intrigues, the expedition's leaders succeeded in moving from San Antonio, but too late to prevent a junction between Spanish commanders Arredondo and Elizondo. On August 18, in the battle of the Medina, the Royalists routed the republicans and filibusters; most of the survivors fled back toward Louisiana. The wounded combatants left on the field were dispatched with sabres.

Arredondo then entered San Antonio and proceeded with the harsh pacification of Texas. In San Antonio royalists shot 327 persons and in Nacogdoches one of Arredondo's lieutenants carried out a similarly bloody purge. Hundreds of refugees began to stream across the Sabine into Louisiana. They left behind them a bloody, barren country; for Arredondo, keeping his sword busy, was restoring Spanish order in Texas by way of killing and wreaking horrible vengeance upon the survivors of the expedition and upon the women and children of Béxar.

Refugees flooded American Louisiana and soon other filibustering expeditions followed, most being organized in New Orleans. Many never got beyond the planning. A few succeeded in moving forces about to no successful end. Several involved pirates and privateers.

All of these schemes, plots, and plans had to be abandoned for a time due to an event known as the Battle of New Orleans. Andrew Jackson, despite the imminent invasion of New Orleans by the British and the proffered support of the Jean and Pierre Lafitte's forces from the pirate colony of Barataria, had no intention of accepting the offer of the "hellish banditti."

The Louisiana Legislature, however, appointed a Committee of Defense, which included a rising young man named Bernard Marigny, a noted swordsman and duelist, to convince Jackson to accept Laffite's offer. They were not, at first, successful. Marigny and the others were instructed to petition the legislature to release those Baratarians imprisoned until the end of hostilities.