Possibly even more handsome than Li Shimin himself. Before the Xuanwu Gate Incident, while the three brothers were locked in fierce struggle, Li Yuan came up with a harebrained scheme to sacrifice the state to save the family: he proposed that Shimin go to Luoyang, establish his own imperial banners, and split the empire in two—thus preserving the house of Li. The TV drama The Age of Zhenguan, drawing on the Zizhi Tongjian, recreated this episode. The brilliant Prince of Qin was noncommittal; he returned to his residence and reportedly feasted and drank with his inner circle through the night. In the end, the Crown Prince blocked the plan, and the matter came to nothing.

Then came the Xuanwu Gate Incident. After it occurred, the Tang dynasty did not manage even an approximately normal succession of power until the reign of Emperor Suzong. The Xuanwu Gate Incident's precedent of resolving succession through illegal, bloody means was absolutely one of the root causes of the palace tragedies in the early Tang.

So—if the Prince of Qin had gone to Luoyang, would things have turned out differently? They certainly would have changed, but likely for the worse. While Li Yuan was alive, he might have maintained a facade of unity. But the moment Li Yuan died, wouldn't the empire have reverted to the pattern of the Eastern and Western Wei—a divided north? Decades of struggle, all for nothing—right back to where things stood before the Sui dynasty.

If east and west had been partitioned, could the two states have coexisted peacefully? If war broke out, countless more people would have died. Even from the Crown Prince's own perspective—could the Crown Prince and the Prince of Qi really have defeated the Prince of Qin, who was literally invincible in battle? Judging from the fact that when the Prince of Qin consulted the military grandee Li Jing before the Xuanwu Gate Incident, Li Jing actually requested to remain neutral—could the Crown Prince and the Prince of Qi even have assembled an army capable of fighting?

So this plan was unworkable. If the Crown Prince hadn't blocked it, he might have lived a few more years. But by blocking it, he prevented national partition and the suffering of the people—which counts, in its way, as a blessing for all living beings.

On another front, the reason Li Yuan proposed this in the first place was that the Prince of Qin genuinely had the power to pull it off, and Luoyang was genuinely his territory. This raises a question: what if the Xuanwu Gate Incident had failed?

The Xuanwu Gate Incident appears to have been a tactical gamble, but it had the conditions necessary for its occurrence. Those conditions were that the Prince of Qin commanded enough force and prestige to quell chaos and restore order. After the Crown Prince and the Prince of Qi were killed, Chang'an barely rippled.

The Prince of Qin's household had prepared a fallback before launching the coup: if the putsch failed, they would flee to Luoyang—merely another version of "sacrifice the state to save the family." Once the Prince of Qin reached Luoyang, what could Li Yuan and the Crown Prince have done about it?

The worst-case scenario would have been the Prince of Qin dying in the coup attempt. In that case, the staff of the Prince of Qin's household and the Tiance Generalissimo's office, along with his former generals in the military—having fought the Crown Prince and the Prince of Qi for so long with all pretenses now stripped away, and now branded with the crime of treason—would have had no choice but to enthrone one of the Prince of Qin's sons and rebel to the bitter end.

Killing the Prince of Qin and then also killing all his sons while the Prince of Qin's household was on high alert—that would have been extraordinarily difficult.

Once the Xuanwu Gate Incident was set in motion, the meritorious clique represented by the Prince of Qin would fight to the finish—until they succeeded or were all dead.

So what actually happened in history was probably the only solution to that deadlock. What else could have been done? Could anyone have asked Li Shimin to simply accept his own death?

On the whole, Li Yuan was a wise sovereign. He successfully held together all the disparate factions of his rebel coalition and gave Li Shimin sufficient trust, enabling the Tang dynasty to complete the great work of unification. Such breadth of vision was exceedingly rare. When we read the story of how Zhao Gou and Qin Hui unjustly executed Yue Fei, we can appreciate Li Yuan's great contribution to pacifying the realm and restoring order in the early Tang.

Yet his vacillation on the question of succession planted the seeds of political turmoil in the early Tang. The Yang Wengan rebellion—though it did contain an element of entrapment by the Prince of Qin—was the Crown Prince not also implicated in treason? If the Crown Prince had been deposed at that point, perhaps he would not have died. Of course, the Crown Prince's faction might not have accepted it, but the weapon of criticism is not, after all, the criticism of weapons.

There has long been a revisionist trend seeking to rehabilitate Li Jiancheng. This is really unnecessary. Everything has its price; the karmic consequences run deep and defy easy comprehension. In his later years, Emperor Taizong saw his beloved son rebel against him and found himself betrayed and abandoned on all sides—was that not tragic? The Li family slaughtered each other in ways too gruesome to look upon, but the people's lives, at least, remained stable. Call it sacrificing the family for the nation. That's what they get for wanting to be emperors.