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How Rain Helped the Mongols Conquer Asia

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In the early 1200s, Genghis Khan united the warring Mongolian tribes into a mobile, efficient military state. Lashing outward in all directions from their home on Central Asia's steppe, the Mongolian armies conquered a large swath of Central Asia in just a few decades. The empire continued to expand under Genghis Khan's descendants and, at its height, was one of the largest in human history, extending from Asia's Pacific coast to Central Europe.

The Great Khan is remembered as a politically savvy leader and a brilliant military tactician, but the rise of his empire, new research suggests, might have also had something to do with a stretch of unusually nice weather.

In 2010, American researchers Neil Pederson and Amy Hessl were in Mongolia's Khangai Mountains, studying the impact of climate change on the country's wildfires. As they drove past an old flow of now-solid lava left by a volcanic eruption thousands of years ago, they saw stands of stunted pine trees growing out of cracks in the lava.

Now, as any budding naturalist can tell you, the annual growth rings of many trees reflect the conditions they grew in. A long, wet growing season results in a wide ring, and a drought-stricken year means a thin ring. After you figure out the age of a tree, these growth patterns can provide a year-by-year record of what the local climate was like. Luckily for Pederson and Hessl, these patterns were written very clearly into the trunks of their Siberian pines, which were well-preserved by the cold, dry conditions of the steppe. The pair had potentially found a wooden record of climate conditions going back thousands of years.

Pederson and Hessl took samples from 17 of the trees and found that they were indeed very old. The innermost rings of some them dated all the way back to the 7th century. Since this discovery, they've gone back and sampled more than a hundred trees in the mountains and the Orkhon Valley region, where Genghis Khan established the seat of his growing empire.

Combining their tree-growth patterns with temperature reconstructions, Pederson, Hessl, and their team pieced together a picture of what the climate was like during the centuries that the Mongols conquered and ruled.

Just before Genghis Khan rose to power, Mongolia's climate was harsh, both physically and politically. The Mongolian tribes warred against each other, and the steppe was cold and stricken by drought. Amid the conflict, the researchers say, the worsening dry conditions of the land could have been an important factor in the collapse of the old order, and paved the way for centralized leadership under Genghis Khan. "What might have been a relatively minor crisis instead developed into decades of warfare and eventually produced a major transformation of Mongol politics," they write.

Then, in the early 13th century, as Genghis Khan unified the tribes, the droughts gave way to a period when the steppes were wetter and warmer than they'd ever been. "This period, characterized by 15 consecutive years of above average moisture in central Mongolia and coinciding with the rise of Genghis Khan, is unprecedented over the last 1,112 years," the researchers say. In addition to being wet, Mongolia at the time was warm, but not exceptionally hot.

In these conditions the Mongolian grasslands would have flourished, providing fuel for the Mongolian war machine. Each of Genghis Khan's mounted warriors used several horses, and the conquering armies brought herds of livestock with them for food and other resources. The dramatic shift in temperature and precipitation came at the perfect time to provide resources for rapid military mobilization and the Mongols' early expansion.

After the empire's initial spasms of growth, the tree ring and temperature data show a return to a cold, dry climate. By then, though, the Mongols had defeated several other Central Asian powers and could exploit the conquered regions instead of relying on the grass of the steppes and their local resources.

The climate shift certainly isn't the only driver of the empire's quick rise; it might have also just been coincidental, the researchers say. To flesh out the picture that the tree rings provide, the team is working on several other studies that could corroborate their ideas. Ecologist Hanqin Tian is developing models to connect the dots between the tree-ring records of weather and grass production. Biologist Avery Cook Shinneman will analyze the layers of fungal spores from animal dung that are trapped in sediment in Mongolian lakes, which could indicate the abundance of the Mongols' livestock. Meanwhile, historian Nicola Di Cosmo will comb through records from Asia and Europe looking for historical references to the climate and the strength of the Mongolian armies.

While the tree rings provide clues about the past climate and its possible influence on the rise of an empire, they also hint that another major shake-up is yet to come in Central Asia. As they did hundreds of years ago, conditions in the region have turned from wet to arid, with long, cold winters and drought-stricken summers comparable to those experienced just before Genghis Khan seized power. During the 2000s, livestock booms went bust; millions of animals died, and hundreds of thousands of displaced herders flocked to the city of Ulaanbaatar.

Those earlier droughts happened in a much cooler climate, though. Central Asia is currently warming more than the global average, and the combination of rising temperatures and droughts, the researchers warn, could mean another era of climate-spurred social and political upheaval.

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The Day Notre Dame Students Pummeled the Ku Klux Klan
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At first glance, there was nothing unusual about the men who stepped off the train in South Bend, Indiana on the morning of May 17, 1924. Dapper and mannered, they drifted from the station to the downtown area. Some headed for a nearby office that sported a red cross made out of light bulbs stationed in the window. Others roamed around looking for Island Park, the site of a planned social gathering.

A closer look at these visitors revealed one common trait: Many were carrying a folded white robe under their arm. Those who had arrived earlier were fully clothed in their uniform and hood, directing automobile traffic to the park.

The Ku Klux Klan had arrived in town.

Fresh off a controversial leadership election in Indianapolis, Indiana, there was no reason for Klansmen to have any apprehension about holding a morale booster in South Bend. Indiana was Klan territory, with an estimated one in three native born white men sworn members within state lines. Just a few months later, Klansman Ed Jackson would be elected governor.

It was only when Klansmen found themselves guided into alleys and surrounded by an irate gang of Catholic students from nearby Notre Dame University that they realized mobilizing in South Bend may have been a very bad idea.

The Klan wanted a rally. What they got was a full-scale riot.

Photo of KKK Indiana Grand Dragon D.C. Stephenson
Indiana Grand Dragon D.C. Stephenson
By IndyStar, Decemeber 12, 1922 issue, Public Domain, Wikimedia Commons

Politically-endorsed prejudice was the order of the day in the early part of the 20th century, when the Klan—first created in 1866 to oppose Republican Reconstruction with violent racial enmity and then revived in 1915—expanded its tentacles to reach law enforcement and civil service. No longer targeting people of color exclusively, the KKK took issue with Catholics, the Jewish faith, and immigrants. An estimated 4 million Americans belonged to the Klan in the 1920s, all echoing the group’s philosophy that only white, God-fearing citizens were worthy of respect.

Under the guidance of Indiana's Grand Dragon D.C. Stephenson, the group had attempted to shift public perception from the lynch mobs of the past to an orderly and articulate assembly. Rallies were held in KKK-friendly areas; propaganda material was becoming an effective weapon for their cause. Acceptance of the Klan’s ideology seeped into political office; Stephenson was a prominent Indiana politician.

To help continue that indoctrination, the Klan made plans for a parade in South Bend to be held on May 17, 1924. That it would be in close proximity to the Notre Dame campus was no mistake: At the time, 75 percent of the school's nearly 2000 students were Catholic, a religion the Klan found abhorrent. By pledging allegiance to the Vatican, their reasoning went, Catholics were acknowledging a foreign power. In the fall of 1923, they had persisted in setting crosses on fire near the University of Dayton in Dayton, Ohio, a predominantly Catholic college, and were frequently chased off by angered football players. That December, the Klan set off firebombs in Dayton during Christmas break. While no one was seriously injured, the intent was to send a message—one they wanted to spread to Indiana.

In the weeks and months leading up to the parade, both students and faculty began to get a taste of that perspective. Copies of the Fiery Cross, the official Klan newspaper, circulated on campus; one Klansman showed up at an auditorium to broadcast that Catholics were not good Americans. He exited the stage when attendees began throwing potatoes at him.

If that public response was foreshadowing, the Klan either ignored or failed to heed the warning. Members began arriving the Friday evening prior to the rally and were met at the train station by irritated students, who scuffled with the early arrivals by ripping their robes. By Saturday morning, when more Klansmen arrived, hundreds of students were in town, a loosely organized anti-Klan task force.

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Klan members were used to breezing into towns without incident. Here, they were immediately confronted by young, ornery college kids proud of their Catholicism. Klansmen were led into alleys and tossed into walls; students who played for the school’s legendary football squad formed wedges, the offensive line-ups found on the field, and plowed into groups of Klan members like they were challenging for a state title.

The violence, swift and sudden, prompted the Klan to retreat to their headquarters in South Bend. The students followed, their blood pumping hot at the sight of the red cross lit in the office window. Below it stood a grocery store with barrels of fresh potatoes. The students lobbed them at the glass, smashing the bulbs inside.

The conflict had been uninterrupted by law enforcement, but not for lack of trying. Deputy Sheriff John Cully, himself a Klansman, tried to enlist the National Guard but was shot down by officials. Notre Dame president Matthew Walsh had already implored students not to go into town, but his words went unheeded.

Unencumbered by authority, the 100 or so students idling near the Klan’s office decided they wanted to seize the hideout. Dozens began running up the stairs but were greeted by a Klan member who produced a gun. Unarmed, the students backed off. Four seniors went back and came to an impromptu truce: The student body would disperse if the Klan agreed to hold their rally without weapons or their robes.

The agreement seemed to placate both sides until Stephenson finally arrived in town before the parade’s scheduled 6:30 p.m. start. Assessing the roughed-up Klansmen and their skittish behavior, he complained to the police, who posted officers on horseback around their assembly at Island Park.

But there would be no rally: A heavy downpour prompted Stephenson to call it off, although the potential for further violence likely weighed on his mind. Lingering students who still hadn’t returned to campus met departing Klansmen as they attempted to drive out of town, smashing windows and even tipping over one car.

By Sunday, things seemed to have settled down. Walsh cringed at newspaper reports of the incidents, fearing it would portray the students as thugs.

Unfortunately, neither side was done protesting. And when they met a second time, the robed men would be backed up by lawman Cully and a squad of 30 deputized Klansmen.

Denver News - The Library of Congress (American Memory Collection), Public Domain, Wikimedia Commons

Students back on campus Monday had taken to hanging up seized Klan robes and hoods on their walls like trophies. It had been a rout, with the Klan barely putting up a fight.

Now, word was spreading through the halls that the Klan had captured or perhaps had even killed a Notre Dame student. Roughly 500 students jogged the two miles back into South Bend, eager for another confrontation.

When they arrived at the Klan’s headquarters, the light bulb cross had been rebuilt. It was an act of defiance, and the students moved forward. But the Klan was prepared: Many had been deputized, and uniformed officers joined the melee. Axe handles and bottles were brandished, and blood began to stain the street. It was a clash, with parties on both sides laid out.

When he got word of the conflict, Walsh rushed to the site and climbed on top of a cannon that was part of a monument. Shouting to be heard, he implored students to return to campus. His voice cut through the sounds of breaking glass, snapping the students out of their reverie. They returned to the school.

Absent any opposition, the Klan did the same. Stragglers from out of town returned home. With bombastic prose, writers for the Fiery Cross later recapped the event by accusing Notre Dame students of “beating women and children.” Later that summer, they declared they’d be returning to South Bend in greater number.

It never happened. Although the Klan maintained an aura of strength for several more years, the conviction of Stephenson for raping and murdering a woman in November 1925 extinguished one of their most enthusiastic leaders; the Depression dampened the ability of new recruits to pay dues. By 1930, the Klan was down to an estimated 45,000 members.

While Walsh never condoned the vigilante justice exacted that weekend, he never disciplined a single student for it.

Additional Sources:
Notre Dame vs. the Klan, by Todd Tucker (Loyola Press, 2004)
"Hearing the Silence: The University of Dayton, the Ku Klux Klan, and Catholic Universities and Colleges in the 1920s" [PDF], by William Vance Trollinger

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Why the Berlin Wall Rose and Fell
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Hulton Archive/Getty Images

One of history's most notorious barriers broke ground early in the morning on August 13, 1961, when East German construction workers, guarded by soldiers and police, began tearing up the Berlin streets.

As European history professor Konrad H. Jarausch explains in this video from Ted-Ed, the roots of the Berlin Wall can be found in the period of instability that followed World War II. When the Allies couldn't decide how to govern Germany, they decided to split up the country between the Federal Republic of Germany in the West and the German Democratic Republic in the East. Eventually, citizens (especially young professionals) began fleeing the GDR for the greater freedoms—and higher salaries—of the West. The wall helped stem the tide, and stabilized the East German economy, but came at great cost to the East's reputation. In the end, the wall lasted less than three decades, as citizen pressures against it mounted.

You can learn more about exactly why the wall went up, and how it came down, in the video below.

[h/t The Kid Should See This]


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