When Ireland and Mexico became one

The Saint Patrick’s Battalion – Batallon de San Patricio – was a military group of Irish and European immigrants who joined the Mexican Army in 1846.

It was 1846 when the U.S. Army invaded Mexico intending to make their country grow. They first established the Republic of Texas in our territory. Then they tried to take the states of Coahuila and Tamaulipas. When the army arrived in Matamoros, a young Irish soldier named John O’Riley began to visit the church in the city.

The U.S. Army became suspicious of him and other young Catholics, as they considered their ideologies more aligned with the Catholic Church than with Washington. This could result in them joining the Mexicans, as they shared the same religion. Their thinking turned out to be correct. This group of Irish Catholics joined Mexico and thus began the history of what we know today as the “St. Patrick’s Battalion.”

Los San Patricios – Painted by Pino Cacucci (2015)

The Irish immigrants saw that fight far differently, as one very similar to their homeland. An arrogant imperial power seizing homes, lands, property of another, smaller, weaker nation of Catholic working people. “While many immigrant soldiers abandoned their posts and others grumbled but made their peace, hundreds of Irish immigrants from tyranny said that they could run no further. Probably knowing their ultimate fate was not a good one, they chose to desert from the U.S. Army and fight injustice in a struggle that they saw as much like the one they had just left in their beloved but occupied homeland.” (Quote by peoplesworld.org / All honor to the San Patricios)

The San Patricios’ was a military group composed of European immigrants, mostly Irish and Germans. It was a mixture of rebellion and desertion because the Europeans were so fed up with the mockery and punishments the Americans gave them for being Catholics that they felt more identified with the Mexicans.

John O’Riley and Patrick Dalton formed a battalion joined by Scots, English, Poles, and French. The group gathered hundreds of soldiers, who took the patron saint of Ireland as their name and banner. 

The San Patricios’ banner 

There are conflicting accounts of the design of the flag of the Saint Patrick’s Battalion. Unfortunately, no flags or depictions of them are known to have survived to the present day. The only version of the flag known to have survived the war was subsequently lost or stolen from the chapel at West Point.

John Riley, who left an account of the battalion, noted the flag in a letter: “In all my letter, I forgot to tell you under what banner we fought so bravely. It was that glorious Emblem of native rights, the banner which should have floated over our native Soil many years ago, it was St. Patrick, the Harp of Erin, the Shamrock upon a green field.”

According to George Wilkins Kendall, an American journalist covering the war with Mexico: “The banner is of green silk, and on one side is a harp, surmounted by the Mexican coat of arms, with a scroll on which is painted Libertad por la Republica Mexicana [Liberty for the Mexican Republic]. Under the harp is the motto of Erin go Bragh! On the other side is a painting … made to represent St. Patrick, in his left hand a key and in his right a crook or staff resting upon a serpent. Underneath is painted San Patricio.was green, with the phrase Erin Go Bragh (Ireland forever) in golden letters. On the other side was an image of the saint who introduced the Catholic religion in Ireland.

 The first combat of the “San Patricios” as part of the Mexican Army was the Battle of Monterrey, on September 21, 1846, with an artillery battery under the command of O’Riley, who assumed the position of commander of this military group. The result was that they managed to avoid two assaults by the Americans on “La Ciudadela.”

The Battle of Monterrey

 After this triumph, the San Patricios grew in number and reached more than 800 men. Therefore, in 1847, Antonio López de Santa Anna converted this group into an infantry battalion and served in the Battle of Churubusco.

 After many bloody and succesful fights they were betrayed and their position was revealed. Several of their key commanders were captured by the United States, tortured, and killed in San Jacinto on September 13, 1847, by order of General Winfield Scott. 

Those who managed to survive the war disappeared. John Riley died at the end of 1850. He was buried in Veracruz under the name of Juan Reley, the same name under which he was registered in the Mexican Army. John O’Riley’s name in the original Irish Gaelic was Seán Ó Raghailligh 

John O’Riley bust in the Plaza San Jacinto, Mexico City.

Currently, there is a commemorative plaque at the place of the execution of the San Patricio Battalion in the San Jacinto Plaza in San Angel. In Merida, a memorial plaque can be seen at Hennessy’s Irish Pub, which its owners, Mr. Sean Hennessy and Mr. Colm Cooney, have displayed in honor of these heroes and martyrs who changed sides to defend what they believed was right, out of pure conviction and ideology. 

This March 17, we remember and celebrate the memory of those brave men who defended Mexico. 

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