The Aztec Empire explained

The Aztec Empire began as a three-city military alliance

The Aztec Empire emerged in 1428 when Tenochtitlan, Texcoco, and Tlacopan formed the Triple Alliance, combining military power and tribute networks. This pact transformed the three city-states into a dominant regional empire that rapidly expanded across central Mexico.

See a 3D reconstruction of Tenochtitlan, the Aztec capital

Mexico City today stands atop Tenochtitlan, the Aztec Empire's capital, founded in the early 1300s. This resource offers detailed 3D models and multiple visual perspectives of the ancient city—displaying its canals, grid layout, temples, and broader Mesoamerican cultural context.

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

Tenochtitlan, the Aztec Venice of Mesoamerica

Tenochtitlan was the capital city of the Aztecs, founded around 1325 on an island in Lake Texcoco, in what is today Mexico. It was a major political, economic, and religious center until its destruction by the Spanish in 1521. This video explores the marvels of the city, which began as an island but grew via causeways and in-filled land and culminating in a North American Venice.

The Aztec capital fell after a brutal 75-day siege

The violent Spanish conquest ended with a 75-day siege of Tenochtitlan, where thousands died as Spanish forces and their Indigenous allies overwhelmed the city of 200,000. This animated explainer breaks down how those alliances enabled the empire’s collapse.

The evolution of Mexico City, from the Aztecs to today

The sprawling modern city situated in the Valley of Mexico began a millennium ago as an island in the middle of Lake Texcoco, connected to land through a series of causeways. Learn how the Aztecs built Tenochtitlan, how the Spaniards conquered it, why the lake disappeared, and more with this visually rich history and geography of a city of 9 million people.

See the path Spanish conquistadors took to conquer the Aztecs

Spanish expeditions reached central Mexico as the Aztec Empire was expanding its influence. After securing bases in the Caribbean, they advanced west into Aztec territory, triggering a cascading conflict depicted in this interactive map and timeline.

Teotihuacán was already ancient when the Aztecs encountered it

By the time the Mexica reached Teotihuacán, the vast city had been abandoned for centuries. First settled around 400 BCE, the inhabitants developed monumental temples, canals, and a carefully planned urban grid centered on the Avenue of the Dead.

What were the Aztecs really like?

Does the society live up to its blood-thirsty stereotype? Archaeologist Eduardo Matos Moctezuma answers this question and more in this short article. Moctezuma was the principal excavator of the major Aztec archaeological site Templo Mayor in the 1970s. He shares how the culture grew from a combined emphasis on war and agriculture, and ruled one of the world's largest cities at the time.

The Valley of Mexico sits over 7,000 feet above sea level

Once dominated by the shallow waters of Lake Texcoco, the high-altitude Valley of Mexico—surrounded by volcanic peaks—was home to the Aztec capital Tenochtitlan. This resource breaks down the region’s unique geography and why it became a cradle of Mesoamerican civilization.

Chichen Itza was one of the Maya world’s most powerful cities

Chichen Itza was a major religious, cultural, and economic center on the northern Yucatán Peninsula, attaining prominence between approximately 800 and 1000 CE. It was largely abandoned by the 13th century for reasons that are still debated today.

Maya civilization explained

The Maya built vast jungle cities that could accommodate up to 50,000 people, developed advanced mathematics—including the concept of zero—and created one of the Americas’ earliest writing systems. Though many cities later declined, their scientific and cultural achievements continue to shape our understanding of the ancient world.

New research challenges the myth that Montezuma peacefully surrendered to Spain

For centuries, historians claimed Montezuma II willingly ceded control to the conquistadors, and that later Aztec resistance was a rogue uprising. Evidence now shows no peaceful handover occurred, revealing a far more turbulent and contested encounter between the two warring empires.

Learn to speak the ancient Aztec language Nahuatl

Across the Aztec Empire, you'd be met with variants of Nahuatl, the indigenous language still spoken by approximately 1.5 million people today. This free, self-paced online university course teaches the Veracruz variant, beginning from the language's "piltlahcuiloltzitzin"—or alphabet—to how to conduct specific "tlamachtiliztli" or ceremonies.

Play a game inspired by Aztec and Mayan mythology

This free online game, Descent of the Serpent, guides players through Mesoamerican myths as they challenge the god Tezcatlipoca. Along the way, it introduces monuments and artifacts with short explanations of their meaning in Aztec and Mayan cultures.

COVID-19 disruptions revived ancient chinampa farming in Mexico City

When the pandemic disrupted food supply chains, chinamperos—farmers who cultivate the Aztec-era “floating gardens” built atop shallow lakebeds—shifted to direct sales in the city, boosting their visibility and reconnecting residents with a longstanding local agricultural tradition.

The Aztecs worshipped Mictecacihuatl, goddess of the underworld

Some elements from ancient festivals honoring Mictecacihuatl and other deities, like incense, skeleton imagery and marigolds, have been incorporated into modern Day of the Dead celebrations, possibly indicating that the holiday blends indigenous and Catholic traditions.

The Aztecs synced their solar calendar with a complex 260-day ritual cycle

Researchers have uncovered how the Aztecs aligned their agricultural solar calendar with a symbolic 260-day ritual calendar, utilizing celestial tracking and monuments. Evidence from ruins and writings explains why their new year corresponded to February 23 on the Gregorian calendar.

The Inca Empire: a timeline

When did the Inca Empire solidify into an empire? When was it invaded by the Spanish? What remains of it today? Click through this timeline to learn more.

The US won every major battle of the Mexican-American War

Despite being outnumbered in key engagements, US forces defeated Mexican armies across every major front. Superior training, leadership, and logistics allowed the US to win decisively—capturing Mexico City without losing a single major battle.

France invaded Mexico to install a puppet monarchy and recover debt

Napoleon III used Mexico's default on foreign loans as cover for a larger imperial ambition: overthrowing President Benito Juárez's government and installing a French-backed monarchy. The Mexican army's surprise victory at Puebla helped delay those plans by nearly a year.

Machu Picchu explained

High in the Andes Mountains, Machu Picchu stands as a testament to the ingenuity and resilience of the Inca Empire. Constructed in the mid-15th century during Emperor Pachacuti’s reign, this site is believed to have served as a royal retreat or ceremonial center. Its engineering marvels, including sophisticated aqueducts, terraced farming systems, and precisely carved stone structures like the Sun Temple, highlight the advanced skills of the Inca civilization.

Ancient Rome explained

Ancient Rome left a high water mark on ancient civilization with its pragmatism and administrative prowess, dominating through its efficient military, engineering, and administration. At least 50 million people—a quarter of the world population—inhabited the empire, covering 5 million square miles at its height.

Support for slavery helped drive Texas to revolt against Mexico

Mexico abolished slavery in 1829, but many Anglo-American settlers in Texas brought enslaved people and refused to comply. Their desire to preserve slavery was a major factor in Texas’s 1836 rebellion and independence from Mexico.

Puebla holds an annual battle reenactment on Cinco de Mayo

Each May 5, the city of Puebla marks the anniversary with festivals and a full military reenactment of the 1862 battle. While Cinco de Mayo is barely observed elsewhere in Mexico, it remains a ceremonial source of local pride in the state where the battle was actually fought.

Tex-Mex is its own distinct cuisine with roots in the Texas borderlands

The cuisine emerged from Tejano cooking, blending northern Mexican ranch food with ingredients such as yellow cheese, beef, and wheat flour. Dishes now considered staples, including chili con carne and fajitas, were Tex-Mex inventions rather than traditional Mexican dishes.

In 1963, a basement renovation in Turkey revealed a passageway to a hidden, multilevel underground city that once housed as many as 20,000 people

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.

Graffiti dates back to at least ancient Pompeii, where citizens scrawled messages to one another on public walls

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement

Tattoos remain visible on your skin thanks to immune cells called macrophages

El Niño, Spanish for 'the boy,' was named after Jesus Christ because the phenomenon resembled the weather changes observed around Christmastime.

View the ten deadliest tornadoes in US history.

The syncytiotrophoblast is the outer layer of the placenta and the largest human cell, spanning an area about twice that of a king-sized bedsheet.

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.

After NASA's Voyager 1 captured Earth as a single pixel as it left the solar system in 1990, astronomer Carl Sagan used the image to reflect on humanity's fragility and the responsibility to protect 'the only world we've ever known.'

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

The term 'algorithm' originated from the Latinized name of al-Khwārizmī, a 9th-century mathematician whose works introduced Arabic numerals and the decimal-based numeral system to Europe and whose treatise 'Al-Jabr' gave algebra its name.

See how fireworks are made and learn how metals like magnesium and copper are responsible for different colors.

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Artificial coral reefs have been 3D printed from nontoxic, biodegradable terracotta clay, which coral polyps have used as a foundation for rebuilding marine ecosystems.

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

The Nasdaq's 'Magnificent 7' companies are responsible for roughly 40% of the Nasdaq 100 index's gains, while the remaining 93 companies account for the other 60%.

Salvador Dalí believed he was his own dead brother, who had died nine months before he was born

Watch contemporary footage covering the US-backed Shah of Iran fleeing the country in the face of the 1979 Iranian Revolution

Quincy Jones' 'Big Band Bossa Nova' helped introduce bossa nova—a jazz-influenced Brazilian genre—to the US

The American cockroach is actually from Africa, an apparent hitchhiker aboard ships carrying enslaved people, with evidence suggesting the bug may have arrived in the New World as early as the 1600s.

Brandi Chastain, the star of the 1999 US victory over China in the 1999 Women's World Cup, was a last-second choice to take the penalty kick that sealed the victory.