The Strategic Corridor of Longshan

Nestled between Shaanxi’s Long County and Gansu’s Zhangjiachuan County lies the ancient Longshan Mountain range—a natural barrier that once dictated the movement of armies and merchants between the Guanzhong Plain and the rugged landscapes of Longyou. Historically, travelers heading to Tianshui in Gansu had no choice but to traverse this formidable terrain, passing through legendary fortresses like Dazhen Pass and Anrong Pass.

The Wei River, originating from Weiyuan, flows eastward through Tianshui toward Baoji. Yet, its steep gorges and cliffs made riverbank travel impossible for ancient armies. Instead, they were forced northward, scaling Longshan’s heights. Here, the Guanshan Grassland—a rare plateau dubbed the “Sky Grassland”—offered respite before the descent into Zhangjiachuan.

Further west lay Longcheng Town, a strategic valley bisected by the Qingshui River and flanked by mountain ranges. This corridor linked Tianshui to Long County, and at its southeastern edge stood the Nüwa Temple. Nearby, a modest Han-style pavilion marked the disputed site of Jieting—the infamous battlefield of the Three Kingdoms era.

The Origins of Jieting’s Strategic Importance

Long before the Three Kingdoms, this region was already a military linchpin. During the Eastern Han, the nearby city of Lueyang was fiercely contested in Emperor Guangwu’s campaigns against warlord Wei Ao. Control of Lueyang meant controlling supply lines to Longshan’s passes—a lesson not lost on later strategists.

By the Three Kingdoms period, Lueyang had been eclipsed by Jieting. For any force moving between Tianshui and Guanzhong, holding Jieting was non-negotiable. It was the gateway for offensives into the plains or the choke point to halt them. Yet, despite its fame, the exact location of Ma Su’s doomed garrison remains debated. While modern markers exist, the true battleground is lost to time.

Zhuge Liang’s First Northern Expedition: Gambits and Miscalculations

In 228 AD, Shu Han’s chancellor Zhuge Liang launched his first Northern Expedition against Cao Wei. The campaign began with a masterful deception: while General Zhao Yun feigned an attack via the Baoye Trail, Zhuge Liang’s main force struck westward through Qishan (modern Xihe County). The surprise worked—three Wei commanderies defected, and Shu’s advance seemed unstoppable.

However, Wei’s response was swift. Emperor Ming relocated to Chang’an, dispatching Zhang He to reinforce Longshan and Cao Zhen to block Zhao Yun. As Zhuge Liang raced to secure the mountain passes, the two armies collided at Jieting.

### Ma Su’s Fatal Error

Shu officer Ma Su arrived first, seizing high ground—a tactically sound move on paper. Yet he fatally ignored water access. The Qingshui River flowed below, but his hilltop camp had no springs. When Zhang He encircled the position, Ma’s troops, parched and desperate, were routed. The loss of Jieting shattered Shu’s supply lines, forcing a full retreat.

Historians still debate Zhuge Liang’s broader strategy. General Wei Yan had proposed a daring strike through Ziwu Valley to Chang’an, banking on Wei commander Xiahou Mao’s incompetence. Zhuge Liang rejected this as reckless, opting for the safer Longyou route. Yet even this “conservative” plan failed at Jieting, exposing Shu’s logistical fragility.

The Domino Effect: How Jieting Altered the Three Kingdoms

Jieting’s fallout was profound. Wei fortified its western defenses, nullifying Shu’s element of surprise. Subsequent Shu expeditions—like the 229 AD Chencang Campaign—faltered against prepared Wei positions. By 231 AD, even Zhuge Liang’s ingenious “wooden ox” supply carts couldn’t overcome Sima Yi’s defensive patience.

Wei’s counteroffensives, like the 230 AD three-pronged invasion of Hanzhong, were thwarted by weather and Shu’s guerrilla tactics (notably Wei Yan’s raids into Qinghai). Yet these were defensive victories. Jieting had already proven that Shu lacked the resources to sustain conquest.

Legacy: The Geography of Destiny

Zhuge Liang’s campaigns underscored a harsh truth: the Qinling Mountains were an insurmountable barrier for Shu. Unlike Liu Bang’s legendary Hanzhong breakout centuries earlier, Shu’s isolated base in Sichuan couldn’t support prolonged warfare. Jieting wasn’t just a battle—it was the moment the Three Kingdoms’ borders crystallized.

Today, the Guanshan Grassland and Jieting’s memorials attract historians and tourists alike. The pavilion overlooking the Qingshui Valley serves as a silent testament to Ma Su’s blunder and Zhuge Liang’s unfulfilled ambition—a reminder that in war, geography often writes the final chapter.