A brief explanation of the story behind the most famous secret crossing in Chinese history.
Cover of a comic book about the sneak attack on Chencang.
Welcome to the Romance of the Three Kingdoms Podcast. This is a supplemental episode.
In this episode, I want to explain a remark made by Sima Yi in episode 123. While discussing Zhuge Liang’s strategy for a future invasion of the kingdom of Wei, Sima Yi told the Wei emperor that he expected Zhuge Liang to emulate Han (2) Xin (4) and make a secret move on a passage called Chencang (2,1). There’s a famous story behind this reference, so let’s delve into it here.
So first, Han Xin is somebody that we have mentioned more than a few times on our podcast. He was one of the most important strategists in the service of Liu Bang, aka the Supreme Ancestor, aka the founder of the Han Dynasty. This particular story dates to after the fall of the Qin Dynasty, which preceded the Han, but before the founding of the Han.
After the Qin fell, the most powerful man in the realm was not Liu Bang, but rather a rival lord named Xiang (4) Yu (3). This Xiang (4) Yu (3) decided to use his power to make himself the strong man of the empire, but he did not try to unite the empire. Instead, he carved the empire into multiple parts and handed them out to the leaders of 18 rebel factions that had risen up against the Qin. Liu Bang was one of those leaders, and Xiang Yu decided to make him the King of Hanzhong, giving him the region of Shu, which of course was where Liu Bei would later establish his kingdom.
Now, Xiang Yu did this for a reason. He recognized Liu Bang as the biggest potential threat to his hegemony. So to make sure Liu Bang couldn’t rise up against him, he assigned Liu Bang to a remote corner of the empire. I mentioned in episode 122 how treacherous the roads into the region of Shu were. Of course, the inverse was also true: It was very difficult getting out of Shu and into the central part of the empire. By sending Liu Bang to this isolated territory, Xiang Yu was making sure that Liu Bang would not be able to make any quick moves toward the Heartlands.
For his part, Liu Bang was quite aware of Xiang Yu’s intentions. To demonstrate to Xiang Yu that he had not thoughts of trying to expand his territory in the future, Liu Bang destroyed the main road into Shu behind him when he entered the region to take his throne. This was a gallery road, meaning a road made of wooden planks that are erected on holes cut into the sides of cliffs. As you can imagine, a road like that was hard enough to traverse in the best circumstances, and now Liu Bang just set the planks on fire to prove that he had no intention of coming back this way again.
But of course, Liu Bang had every intention of expanding his territory in the future. A while later, when he had built up sufficient strength, Liu Bang began thinking about how he was going to do that. The first challenge, of course, was simply getting out of Shu. The key point on the route from Shu into the Heartlands was the passage at Chencang. This place had natural geographical barriers from the surrounding mountains, and Xiang Yu had also stationed a sizable force here to keep watch on this most important locale.
Now, the main road from Shu to Chencang was none other than the gallery road that Liu Bang had burned when he entered the region, so that was problem No. 1. He had done such a good job of convincing Xiang Yu that he wasn’t planning on coming back out into the Heartlands that it would take years to repair the road to the point that it could be traversed by an army. And by then, the enemy would have seen you coming from miles and years away and no doubt would be prepared. So what’s an ambitious Supreme Ancestor to do?
At this point, Han Xin offered an idea to Liu Bang. Liu Bang immediately dispatched his most trusted general to lead 10,000 men to go repair the gallery road he had destroyed, with the order that they must be done within a month. Yes, a month. And yes, I did just say that a work of this magnitude would take years to complete. Now, the army that Xiang Yu had stationed at Chencang knew this as well, so when they saw these guys out there scrambling on a construction project that they knew would take years, they simply snickered and went about their day-to-day business. It was going to be a long time before the enemy would be able to come anywhere close to their location, so why sweat it?
BUT, unbeknownst to them, while those 10,000 men were busy repairing the main road and occupying their attention, Liu Bang was leading crack troops and sneaking down some mountain road that only he knew about. They were able to get the jump on the enemy forces at Chencang and took the passage, launching Liu Bang’s eventually successful quest to conquer the empire.
So this event has become so well known that it has become an idiom: Repairing the gallery road in appearance, but sneaking through Chencang in secret. Often times, that is shortened to just “sneaking through Chencang.” This idiom is usually used as a broader metaphor for any kind of misdirection play. In the novel, however, Sima Yi was invoking this story to say that Zhuge Liang was literally planning to sneak up on Chencang.
Alright, so now you know the history behind that reference. I hope you enjoyed this supplemental episode, and I’ll see you next time on the Romance of the Three Kingdoms Podcast. Thanks for listening!