|Stone inscription detailing a sortie of Ye Bu Shou on Qinhuangdao Great Wall.|
Jian Shao (尖哨)
While formally enlisted by Ming army, neither Jian Er Shou nor Ye Bu Shou operated under a unified organisation. Each garrison, border outpost and commander maintained their own units for different purposes. Nevertheless, in order to fulfil their main responsibilities – reconnaissace, espionage and intelligence gathering, Jian Er Shou and Ye Bu Shou were organised into Jian Shao (尖哨, lit. 'Sharp sentry') units irrespective of their administrative structure. Jian Shao could be further divided into Ming Shao (明哨, lit. 'Bright sentry') and An Shao (暗哨, lit. 'Dark sentry') that served different purposes.
Ming Shao, consisted of majority Jian Er Shou, were the active branch of Jian Shao. They were spies that actively infiltrated enemy ranks to gather intelligence. Once they successfully infiltrated, Ming Shao were supported by Ban Ling (伴領, lit. 'Companion-guide'), access/sleeper agents that consisted of mostly defectors.
On the other hand, An Shao consisted of both Jian Er Shou and Ye Bu Shou and were the passive (in the sense that they did not actively seek out enemy intelligence, but acted as observers) branch of Jian Shao. They were long range reconnaissance patrols that maintained covert observation posts and monitored enemy movements. An Shao were also responsible for relaying early warnings of impending attack back to the garrisons should the Ming Shao get caught or otherwise unable to fulfil their tasks.
Despite both branches were grouped under Jian Shao, Ming Shao and An Shao operated independently from one another. In fact, agents from both branches were explicitly forbidden from making contact with each other.
Ye Bu Shou (夜不收)
The accurate meaning of Ye Bu Shou was "one that does not get off work after nightfall". True to their name, Ye Bu Shou were night operation specialists of the Ming army and served many roles beyond reconnaissance, especially those that required standing vigil during the night. Ye Bu Shou manned warning beacon towers, served as night watchers, signallers, messengers and mounted short range (less than one hundred li from the border) reconnaissance patrols. They also engaged in direct action and unconventional warfare operations behind enemy lines, as well as espionage activities such as sedition and instigate defection. Some commanders also employed Ye Bu Shou as bodyguards, investigators, and prisoner escorts.
Both Jian Shao and Ye Bu Shou acted as forward scout for Ming army during the seasonal Shao Huang (燒荒) operation, establishing security perimeter to ensure the safety of the main army that conducted the burning of Mongol pastures. Some Ye Bu Shou also participated in the burning themselves.
Recruitment and Training
The works of Jian Er Shou and Ye Bu Shou were physically demanding, thus the recruits must be healthy and fit. Quickness of foot as well as stealth capability were especially prized, as were will, courage, calmness, wit and knowledge. As their works always accompanied great risks, Jian Er Shou and Ye Bu Shou were among the most well-paid troops of the Ming army, earning double pay compared to regular troops. Agents that successfully discovered crucial intelligence were rewarded handsomely, and the families of those that lose their life on duty were compensated.
As each garrison and commander handled their own recruitment, Jian Er Shou and Ye Bu Shou came from many backgrounds. Many commanders recruited among regular border troops, whom were already used to harsh military lifestyle. Other Jian Er Shou and Ye Bu Shou were recruited from border dwellers, former captives and enemy defectors, given that local knowledge and ability to speak enemy's language were crucial to espionage activities.
Most of these fresh recruits lacked military experience or espionage training, or both, and had to undergo extensive training before they were ready to be fielded. Whenever possible, Jian Er Shou and Ye Bu Shou on active duty were recalled for retraining every half a year, and they underwent performance assessment frequently. Some commanders also demanded their Jian Er Shou and Ye Bu Shou to train alongside regular troops.
Due to myriad of roles that Jian Er Shou and Ye Bu Shou needed to fulfil, their equipment varied wildly from one another. A Ye Bu Shou guarding a warning beacon tower would have been equipped similarly to a regular troop, while his comrades in the field would be lightly armed, but were given signalling equipment such as signal cannons and paper bombs.
Scouts and spies that operated deep inside enemy territories were dressed in Mongolian clothing and rode Mongol horses (as Mongols knew their horses better than men, they could easily tell apart a Chinese horse from a Mongol one). As these agents often operated far away from the main army for extended period of time, they were minimally supplied and had to forage from enemy territory.
Other equipment of note were special, concealable horn bows and bamboo poison arrows designed to kill horse, used by Ye Bu Shou saboteurs (as horse was Mongol's most important asset). Ye Bu Shou also used swords, war axes and grenades for night raids.
Spy, Scout and Special Force
While the concepts of reconnaissance, espionage and special operations were almost as old as the warfare itself, Jian Er Shou and Ye Bu Shou were some of the earliest military units specifically raised and trained for these roles. The four-layer intelligence and early warning network operated by Jian Ye, consisted of Ming Shao (spies), An Shao (reconnaissance), Jia Pao (架炮, lit. 'Mounting cannon', signallers) and Dun Hou (墩堠, border outposts), was an enormous step up from the ad hoc scouting parties employed by other militaries of the time. Their ability to successfully infiltrate enemies that had completely different language, customs, values and lifestyle was a testament of their competence.
Despite their effectiveness, Jian Ye were not the only agents operating at the border. They often coorporated with other agents such as Tong Shi (通事, lit. 'Know-how', translator that later also served as spy) and personal agents under direct employment of individual commanders or civil officials, although this sometime resulted in interservice rivalry. Ye Bu Shou also shared some of their responsibilities with other units such as Tang Bao (塘報, reconnaissance and messenger unit) and Dun Jun (墩軍, lit. 'Outpost army', military unit tasked with guarding outposts and operating beacon towers), and they often worked together.
Nevertheless, enemies of the Ming were far from helpless against the infiltration of Ming agents. The Mongols were themselves well-versed in the art of espionage, and regularly attempted to purge the spies among their ranks or fed them false intelligence. Many Jian Ye were killed on duty, while others were offered bribe and defected. On some occasions, Jian Ye were captured for ransom instead. By late Ming period, Jurchens (later Manchu) even conducted counterintelligence operations known as Zhuo Sheng (捉生, helen zhafambi in Manchu language, lit. 'Capture alive') that specifically targeted Ming agents.