deed that was eventually accomplished by the Sui and Tang. In addition to preparing us to address the common threads in these cases, it may also help explain why the two Tuoba political as well as biological heirs were so anxious to claim their alleged Chinese ancestry.
The Succession to the Throne in the Early Tang
The case of Prince Chengqian was hardly an aberration in the imperial family as the official records would have us believe. As I demonstrate, one of many characteristics that set the Tang apart from other native Chinese dynasties was the persistent political struggle concerning the succession of the throne. During a period that covered nearly the first century and a half of the dynasty, not once did the succession follow the time-honored Hàn dizhang primogeniture principle. Nor was there a single time that the process ran smoothly, without strife (and indeed bloodshed). Even after that, as observed by Chen Yinke,37 the position of the official heir apparent (by the dizhang rule or not) was anything but firmly established.
It should be pointed out that exactly on this point the supposedly native Tang dynasty was strikingly akin to the Qing regime, a typical conquest dynasty in the conventional categorization. The latter, unburdened by the need to maintain a Hàn Chinese façade, simply (after a period of failed experimentation) abolished the institution of an heir apparent altogether.
This similarity points to the root of the incessant succession struggles of the Tang: the imperial house's Turco-Xianbei Steppe origin and heritage. The magnitude and duration of this entirely unique (among the so-called native dynasties) characteristic are far too great to be ascribed simply to some lingering Northern influences. It is the reflection of the true ethnic/cultural identity of an imperial house that had spared no efforts to present itself as a bona fide Hàn regime in all historical records.
One cannot help noticing the numerous succession struggles in the Western Jin and the Southern dynasties. However, in addition to the Northern influence38 and often direct involvement, exemplified by the case of Liu Yuan, the founding emperor of the Xiongnu Former Zhao dynasty (Jin shu 101.2648 and passim), these incidents all fall into the general feature of every new native dynasty that, largely as the ripple effect of the preceding military campaigns and difficulties in establishing a new imperial order, the first and sometimes the second succession were invariably problematic. In essence, none of the native dynasties mentioned here survived much beyond this bottleneck, whereas the only long-lived native house during the period, namely the Eastern Jin (317–420), was remarkably free of similar trouble. Furthermore, the struggles during the Southern dynasties all had extensive external involvement, while the Tang cases (and many of their precedents in the Northern Turco-Xianbei courts), as observed by Chen Yinke, were all confined to the capital area within the imperial clan.
The disruptive and often bloody succession process of the Turco-Mongol regimes on the Steppe characterized by fratricide and other forms of bloodshed within the ruling house has long been noted. However, the most methodical treatment of the subject appears to be that of the late Joseph Fletcher. He used the term “blood tanistry” for the general principle on the Steppe that the leadership of a tribe or other polity should be passed on to the best qualified member of the chiefly or ruling house.39 And the eventual choice of a new leader was usually the result of some form of contention. Fletcher discussed in detail how this Turco-Mongol tradition manifested itself in the Ottoman Empire.40
Peter Boodberg was among the first to ascribe this characteristic to Turco-Mongol traditions, including the not-unusual father-son enmity in particular, in discussing the Sui imperial succession.41 In an unpublished presentation on blood tanistry in Ottoman, Indian, and later Chinese (Jin, Yuan, Ming, and Qing dynasties) regimes, Fletcher also mentioned briefly the Sui case and the case of Li Shimin.42 Nonetheless, as I demonstrate, this tradition was in fact much more than what Fletcher called “traces” in the history of the Tang, which would also reveal some interesting phenomena in what had been traditionally called the process of sinicization.
Let me briefly review the long history of succession struggles in the first two centuries of the Tang.
This uninterrupted stretch started with Li Shimin. The future Emperor Taizong's meticulously planned and impeccably executed maneuver to replace his elder brother Jiancheng as the heir apparent culminated in the famous Xuanwu Gate coup d'état in 626. Later I discuss other aspects reflected in this blatant challenge to the time-honored dizhang principle. But not as well known was the observation by the Qing historian Zhao Yi that this murderous fratricide extending to the execution of all male offspring of the two slain brothers almost developed into a case of patricide as well,43 as is generally believed regarding the Sui emperor Yangdi's accession to the throne.
A very similar drama would be staged under the reign of Taizong by his sons, though with somewhat different endings due to changed circumstances and personalities, whose implications will be discussed later. It is worth noting that in the aftermath of the alleged patricide/fratricide scheme of 643 plotted by Taizong's original heir apparent, Prince Chengqian, the choice of the new crown prince was partially prompted by the need to avoid future fratricide (ZZTJ 197.6197, 199.6280–81), which of course did not at all prevent it from happening after the death of Emperor Taizong. Another episode was the promise by one of the players, Li Tai (Prince Wei), to kill off his son if he was appointed heir apparent, so that after his death the throne would go laterally to another son of Taizong (ZZTJ 197.6195). This promise did not sound so unnatural to Taizong's ears (and indeed, as we shall see, would be redeemed en masse by a great-grandson of his).
Into the reign of the next emperor, and with the emergence of a strong woman, Wu Zetian, the focus of the succession struggle shifted somewhat from brotherly contest to acute parent-child enmity. Empress Wu showed little hesitation in having two heirs apparent, both her own sons, killed in 675 and 684 respectively (ZZTJ 202.6377, 203.6419.). A few modern authors,44 who contrast her apparent lack of qualms with a mother's natural feelings and argue that one of the princes was perhaps not born of Empress Wu, do not seem to recognize the entrenched tradition of filicide in the Sui and Tang houses and Empress Wu's merciless killing of her own baby daughter and several grandchildren later in her life (ZZTJ 199.6286–87, 204.6467, 207.6557).
What is more interesting is that, after having deposed two puppet emperors, both her own sons, and enthroned herself, Empress Wu had put both under house arrest with strict court supervision that effectively cut off all communication with the outside (ZZTJ 204.6473, 205.6490). The empress recognized that she would still have to pass on the throne to no one else but her blood offspring in the end (ZZTJ 204.6474–75, 206.6526–27). This awkward situation bears a striking resemblance to the Ottoman court's Kafes (cage) system.45 This measure, perhaps in a less draconian form but nonetheless “violating fundamental human relations by incarcerating one's flesh and blood,” would be institutionized by Emperor Xuanzong and enforced at least beyond the year 833 (ZZTJ 244.7886).
One may also note that the Ottoman Kafes was hardly unique to the Turkic political sphere: the later Ghaznavids in Afghanistan and Northern India also developed a similar policy after incessant succession struggles among the sultan's family members.46 Corresponding to the birth control measures in the Kafes, a remarkable circumstance was the repeated attempts by Emperor Xuan-zong (then the crown prince) to abort his consort's pregnancy for fear of further antagonizing Princess Taiping (Jiu Tang shu 52.2184). One notes that the incident was recorded due largely to the fact that the pregnancy the future Emperor Xuanzong tried to terminate produced in the end none other than the future Emperor Suzong (reign 756–62).
After the restoration (705) of the Tang dynasty under Empress Wu's son Emperor Zhongzong, we soon see another case of filicide in a succession struggle: the killing of Emperor Zhongzong's heir apparent, Prince Chongjun, after the latter's failed coup attempt against his father (ZZTJ 208.6611–12). But not long afterward the emperor in 710 fell victim of viricide/patricide as his empress and his daughter Princess Anle conspired to grab the imperial power for themselves (ZZTJ 209.6641–42).
In a typical Turco-Mongol maneuver after the death of the khan, and against the age-old tradition of lineal succession in the Central