1. Xue coax the emperor to cross the sea: In the Tang Dynasty, Emperor Taizong personally conquered North Korea. When he arrived at the seaside, he hesitated for fear of crossing the sea. Xue designed a banquet for Tang Taizong to cross the sea smoothly, so that Tang Taizong could cross the sea by boat without knowing it.
2.
Emperor Wendi of Sui Dynasty destroyed the Chen Dynasty: After the unification of the North, Emperor Wendi of Sui Dynasty found that the national strength of the Chen Dynasty was empty, so he adopted the strategy of "crossing the sea from heaven" and attacked Chen by several armies. Sui Jun first sent troops to cut off the links between the upper reaches of the Yangtze River and the troops in the middle and lower reaches, and then sent general He Rebi to lead Sui Jun to attack Jiankang. He Ruobi frequently organized troops to relieve the north bank of the Yangtze River, creating an atmosphere of bravado, which made Chen's army mistakenly think that it was about to attack. When Chen Chao's troops let their guard down, Sui Jun suddenly attacked and successfully destroyed Chen Chao.
3.
Zhong Er, the son of the State of Jin in the Spring and Autumn Period: Zhong Er, the son of the State of Jin, was drunk by Qi Jiang and Hu Yan on his way to escape and sent him away from the State of Qi by the trick of "crossing the sea from heaven".
4. He Ruobi was conquered by the Sui Dynasty: When He Ruobi attacked the southern part of Xuzhou, the state of Chen, he changed his defenses many times with great fanfare and paralyzed the enemy. Finally, while the enemy was unprepared, he commanded the army to sneak attack and conquer the south of Xuzhou.
5. Julius Caesar in ancient Rome: When Julius Caesar conquered Gaul (present-day France), he adopted the strategy of "hiding the sky and crossing the sea", made the Gaul army relax its vigilance through illusion and deception, and then launched a surprise attack.
6.
Normandy Landing in World War II: In the Normandy Landing Campaign of 1944, the Allies successfully deceived the Germans through a series of deceptive actions, including using fake tanks, fake planes and fake soldiers, and through encrypted communication and false information, which made the Germans misjudge the landing location and scale of the Allies.
These cases show that the strategy of "crossing the sea from the sky" has been widely used in the history of ancient and modern China and foreign countries, and has achieved varying degrees of success.