When people think of the Chinese Red Army's Long March, images may range from late Chinese leader Mao Zedong and the epic journey itself to "Red Star Over China," the landmark book by American journalist Edgar Snow.

But why did the Red Army embark on the Long March? How far did the soldiers travel, and what did they endure along the way?

This year marks the 90th anniversary of the victory of Long March, offering a chance to revisit what Snow called "an odyssey unequaled in modern times" and explore why the epic journey remains a defining chapter in modern Chinese history.

'An odyssey unequaled in modern times'

The Long March began in October 1934, when the main forces of the Chinese Red Army, the forerunner of the People's Liberation Army, were forced to break out of their revolutionary base areas in east China's Jiangxi Province after being surrounded by the much larger forces of the Kuomintang Party during the Chinese civil war.

Over the next two years, different Red Army forces crossed raging rivers, climbed snow-capped mountains and traversed vast grasslands across more than 10 provinces, fighting their way out of Kuomintang military encirclement while preserving their strength.

The march lasted from October 1934 to October 1936. While estimates of the total distance vary, Mao told Edgar Snow that the Red Army had traveled 25,000 li, or roughly 12,500 kilometers. The journey consequently became known as the "Long March of 25,000 li."

Battle of the Xiangjiang River: One of the bloodiest encounters

The trek began in Yudu County in Jiangxi Province in October 1934. The Red Army is estimated to have fought more than 600 battles and skirmishes during the Long March, suffering enormous losses along the way.

One of the bloodiest early encounters came at the Xiangjiang River in south China's Guangxi Zhuang Autonomous Region in November 1934.

The Central Red Army, whose soldiers were on average under 20 years old, suffered heavy casualties in the battle. It numbered 86,000 when it set out, but only just over 30,000 made it to the end.

Among those who fought was 29-year-old commander Chen Shuxiang of the 34th Division of the Fifth Army Corps. Wounded and captured, Chen refused to surrender and chose to die rather than give in.

The enormous sacrifices reflected the determination of many Red Army soldiers to continue fighting despite the overwhelming odds against them.

Yet the heavy losses also brought the Red Army to a critical turning point.

Zunyi Meeting: A turning point

From January 15 to 17, 1935, the Political Bureau of the Communist Party of China (CPC) Central Committee held an expanded meeting in Zunyi, southwest China's Guizhou Province.

The meeting addressed two fundamental questions: how to respond to the military setbacks the Red Army had suffered, and how to resolve problems within the Party's leadership and organization.

It criticized mistakes made by the military leadership at the time and reaffirmed Mao Zedong's military approach.

According to Xia Lu, a CPC expert at Renmin University of China, after the meeting, the Party and the Red Army began to move from a position of danger toward greater security, while the course of the Chinese revolution shifted from setbacks toward a series of strategic successes.

Hard-won victories

One of the clearest examples came soon afterward at the Chishui River, which flows through southwest China's Guizhou, Yunnan and Sichuan provinces. From January 19 to March 22, 1935, about 30,000 Red Army soldiers crossed the river back and forth four times while facing an enemy force of roughly 400,000 troops. The maneuver enabled the Red Army to break out of the military encirclement while preserving much of its core fighting strength.

Another defining moment came at Luding Bridge in May 1935. With Kuomintang forces in pursuit, the Red Army reached Anshunchang on the Dadu River in western Sichuan Province, where Luding Bridge was the only viable crossing. But the chain bridge had been stripped of its wooden planks.

To reach the bridge, a vanguard regiment covered about 120 kilometers in a single day. On the morning of May 29, 22 volunteer soldiers crawled across the exposed iron chains under heavy machine-gun fire and attacked the enemy-held positions on the opposite side.

Their advance secured the bridge and opened a vital route for the main force of the Red Army to cross the Dadu River and continue northward.

Fighting nature as well as the enemy

The challenges did not end with the battles. After crossing the Dadu River, the Red Army climbed snow-covered mountains and traversed vast, largely uninhabited grasslands. Supplies dwindled, while altitude, cold and difficult terrain posed new threats.

Many soldiers suffered from severe altitude sickness, hunger and thirst, freezing temperatures and the dangers of crossing marshlands.

Wang Chaoguang, former director of the Institute of World History at the Chinese Academy of Social Sciences, told Beijing Review that many Red Army soldiers perished amid these brutal conditions rather than in combat. "Countless comrades gave their lives along the way," Wang said, adding that only 57,000 from the originally 206,000 people survived at its end.

By October 1936, the two-year trek was drawing to a close. Red Army forces from different routes finally joined in Huining County, northwest China's Gansu Province, marking the completion of the Long March.

The journey had begun as a desperate effort to break out of encirclement. It ended as a defining turning point in the history of the CPC and the Chinese revolution.

(With input from Xinhua)