A rare 15th-century royal document from Louis XI's court was identified using advanced imaging after it went unnoticed for years in a University of Toronto collection.

Archaeologists have uncovered a cannonball that may have been fired during the 1836 Battle of the Alamo — just three months after making a similar rare discovery.

The cannonball was discovered on June 2. 

The Alamo Trust, the nonprofit organization that oversees the Alamo Mission, announced the discovery on June 16.

SECRETS OF REVOLUTIONARY WAR BATTLEFIELDS EMERGE 250 YEARS AFTER AMERICA'S FOUNDING

It was found outside the northeast corner of the Alamo Church, in an adjacent excavation unit where another intact cannonball was unearthed in March.

Pictures show heavy rust covering the newly discovered iron cannonball, which appears orange-brown in color.

Archaeologists in Texas have uncovered a second cannonball that may date to the 1836 Battle of the Alamo. (Alamo Trust; Kean Collection/Getty Images)

Because it was found at roughly the same depth as the first cannonball in a neighboring excavation unit, archaeologists believe it likely remained undisturbed for nearly 190 years.

"So whenever they were dropped, the very first time — possibly in 1836, probably — they haven’t been touched since," Tiffany Lindley, director of archaeology at the Alamo, said in a press release.

ANCIENT VIKING SWORD DISCOVERED 'STICKING UP OUT OF THE GROUND' AFTER 1,300 YEARS

"And that’s what makes them extra special."

One of the most important conflicts in Texas history, the Battle of the Alamo was fought between Mexican forces and Texian rebels.

Researchers believe the newly uncovered cannonball may have remained undisturbed for nearly 190 years beneath the historic site. (Alamo Trust; Stock Montage/Getty Images)

Lasting from Feb. 23 to Mar. 6, 1836, the battle saw Texian forces — including Davy Crockett and William B. Travis — hold off a much larger Mexican army.

The 13-day siege ended with Mexican troops overrunning the Texian defenders, a loss that became a rallying cry for the Texas Revolution.

CLICK HERE TO SIGN UP FOR OUR LIFESTYLE NEWSLETTER

Researchers were surprised to find the second cannonball, Lindley told Fox News Digital.

She said the site has undergone extensive use over the years, including occupation by the U.S. military quartermaster and commercial development around the historic grounds.

"We find what gets left behind, and often that means broken and discarded items."

"All of that has impacted a significant portion of the underground resources," said Lindley.

"It was amazing to find one cannonball, and then to follow it up a couple of months later with a second was quite surprising."

CLICK HERE FOR MORE LIFESTYLE STORIES

The recently found cannonball "isn't as well-preserved as the first due to the type of metal," said Lindley.

The first one was made of solid bronze, while the second one is made from solid iron.

Researchers were surprised to uncover a second cannonball just months after making a similar discovery nearby. (Alamo Trust)

"However, it's still in pretty good condition," she added. "We are hoping to send both artifacts off for conservation."

While the team hopes to find more artifacts related to the Battle of the Alamo, Lindley said the excavation yields dozens of historic finds every day.

TEST YOURSELF WITH OUR LATEST LIFESTYLE QUIZ

"We are finding dozens of exciting historic artifacts every day, along with hundreds of maybe not so exciting artifacts, like nails and brick," said Lindley.

"We find what gets left behind, and often that means broken and discarded items."

The cannonball "is still in pretty good condition," said Lindley. (Alamo Trust)

Lindley added that, though exciting, the cannonball is only "one small part in this project."

CLICK HERE TO DOWNLOAD THE FOX NEWS APP

"After excavations end, analysis of the data will provide valuable insight into the daily lives of the inhabitants of the site," she said.

Andrea Margolis is a lifestyle reporter for Fox News Digital and Fox Business. Readers can follow her on X at @andreamargs or send story tips to andrea.margolis@fox.com.

A look at the top-trending stories in food, relationships, great outdoors and more.

By entering your email and clicking the Subscribe button, you agree to the Fox News 
        Privacy Policy
       and 
        Terms of Use
      , and
      agree to receive content and promotional communications from Fox News. You understand that you can
      opt-out at any time.

Subscribed

You've successfully subscribed to this newsletter!