The Battle of Guandu was a battle taking place at the Yellow River in 200 AD.

It was a crucial victory for the leader Tsao Tsao (155 AD - 220 AD) in which he led a rebellion against Yuan Shao. He destroyed Yuan Shao's supplies and killed him. This resulted in Tsao Tsao becoming the military ruler of northern China.

From 196 onwards it became increasingly clear that there would be a confrontation between the two warlords Yuan Shao and Tsao Tsao for dominion of the north sooner or later. In such an eventuality, the position of Guandu would become of strategic importance. It was close to the Yan Ford on the Yellow River and lay directly on the route to Xuchang. Tsao Tsao was the first to recognize its importance and in the autumn of 199, he moved forces there and prepared fortifications. The next year, Liu Bei defected from Tsao to his rival Yuan Shao. Yuan took the opportunity to mount a campaign in the south and in the first month of 200, his vanguard attacked the garrison of Liyang, just north of the Yellow River. The commander at Liyang, Yu Jin, signalled to headquarters the approach of Yuan Shao. Tsao Tsao immediately regrouped his troops and stationed 20,000 men at Guandu in preparation for a decisive battle in the new future.

Soon Yuan Shao's main army arrived, boosting his numbers to 110,000, including 10,000 cavalry. His general Yan Liang crossed the Yellow River and attacked the city of Baima. Under the advise of Xun Yu, Tsao Tsao led a battalion across the Yan Ford on the Yellow River. But this manoevre proved to be only a feint, and as soon as Yuan Shao drew troops from Baima to counter Tsao's attack, Tsao Tsao retreated and struck east to relieve Baima. In the ensuring battle, General Yan Liang was killed and the Yuan troops disastrously routed. After this Tsao Tsao prepared to abandon the city and evacuated the residents south. Taking advantage of the situation, Wen Chou and Liu Bei, leading 6,000 light cavalry, were sent from the Yuan camp in pursuit. But again, Tsao Tsao anticipated his opponents' move and had prepared a snare. Horses, equipment and other valuables were discarded and as the enemy troops broke ranks to loot, they were smashed by six hundred elite cavalry. In the chaotic slaughter, the commander Wen Chou was killed. Thus, in the opening moves, Yuan Shao had lost two of his great leaders and his army morale had taken a huge thrashing.

In the aftermath, he reorganised his forces and Liu Bei was sent out to attack Runan, and expose Tsao Tsao's flank. Ever the strategist, Tsao Tsao recognised this and wary of fighting under disadvantageous circumstances, commanded a general withdraw to Guandu. At the same time, Tsao Ren and Yu Jin were sent to harass the enemy rear. Orders were given for administrators to govern leniently to offset any chance of civilian disruptions in the rear. In the eighth month the Yuan army pushed to Yangwu, directly north of Guandu and began construction on earthen fortifications. The Cao army also began reinforcing their own defences. Both sides harassed each other with ballistas and catapults without effective result. To break the stalemate, it was suggested to Yuan Shao that he use his superior numbers to his advantage and outflank the enemy to attack Xuchang. Yuan, however refused, preferring to wait for the food supply in the Cao army to run out.

Indeed the grain was falling short in Tsao Tsao's granaries and he considered a withdrawal. Such a situation called for immediate action. Shock troops were dispatched to burn Yuan's grain carts and Yuan Shao was forced to send out for relief food supplies. In the tenth month, Chunyu Qiong's ten thousand-strong force returned with large reserves of grain and lodged around twenty kilometres from the main Yuan camp, in a place called Crow's Nest (Wuchao). The wisdom of such a position was questioned by adjutant Ju Shou, who argued that there were too few troops to guard such an important commodity as grain. A defection soon after from Yuan Shao's ranks alerted Tsao Tsao to this weakness and he seized the opportunity. Leaving the main camp in the hands of Tsao Hong, a force of 5,000 elite infantry was led by Tsao Tsao himself into enemy controlled territory.

Travelling rapidly under the enemy banner at night and feigning to be Yuan's reinforcements, Tsao Tsao besieged Chunyu Qiong's garrison and destroyed grain carts. At such a time of emergency, Yuan Shao refused to send his main forces to relieve Chunyu's defenders, as his commander Zhang He urged him to do. Instead he chose to send a smaller force of light cavalry, whilst attacking Guandu with the bulk of his army. By dawn, Wuchao had fallen to the furious attack and Tsao's victorious soldiers then proceeded to defeat the small relief force. At Guandu, Yuan Shao failed to break through and army morale dropped sharply in knowledge of the capture of food supplies. Zhang He surrendered and his battalion burned their weapons. Tsao Tsao seized the day once more and attacked when the enemy was at its weakest. 70,000 of Yuan's force was destroyed and he lost countless provisions, escaping over the Yellow River with little more than 800 horseman.

The victory was a decisive one; Yuan Shao no longer provided a serious threat to Tsao Tsao's ambitions and he died a dejected man the next year. Unlike Yuan Shao, Tsao knew the value of tactical withdrawals. On the strategic level he could understand and anticipate his opponent's moves and took calculated risks to counter them. The victory of Tsao Tsao over superior forces lay in his capacity for superior planning and processes on tactical and strategic levels. He rendered his inferior numbers irrelevant with the use of disruption and dislocation. In short, dislocation is the art of cancelling out the enemy's strength. Instead of having to fight a hostile force on its own terms, the friendly force avoids any combat in which the enemy can bring his might to bear. In contrast, Yuan Shao had none of this brilliance and has often been criticised for not heeding the reasonable suggestions of his senior advisers. Certainly this was an important part of his defeat, for if he should have recognised the importance of the grain supply and taken appropriate measures as his counselors advised. The Battle of Guandu will forever be testimony to the fact that superior numbers do not gain victory.