adherents. The largest Twelver populations are
located in iran and iraq, where there are about
58.9 million (90 percent, est. 2007) and 17 million
(60–65 percent, est. 2007) adherents, respectively.
Twelvers are also majorities in Azerbaijan (85
percent) and Bahrain (70 percent); they are large
minorities in lebanon (30 percent), Kuwait (25
percent), the United Arab Emirates (16 percent),
saUdi arabia (15 percent), aFghanistan (19 per-
cent), Tajikistan (5 percent), pakistan (18–20 per-
cent), and india (2–5 percent). In addition, since
the latter part of the 20th century, small immigrant
communities of Twelver Shii Muslims have arisen
in Europe, the United Kingdom, the United States,
and Canada. Although Twelvers have often avoided
overt involvement in politics, and developed reli-
gious doctrines to make this permissible, their
understanding of Islam changed significantly in the
latter part of the 20th century, leading to what some
scholars have called a “revival” of political Shiism.
bEGINNINGS
The historical roots of Twelve-Imam Shiism date
back to the crisis that confronted the early Mus-
lim community in Medina when Muhammad died
in 632, before succession to leadership had been
clearly determined. Arabian society was strongly
patrilineal, but Muhammad had no sons to suc-
ceed him. The consensus of leading members
of the umma was that Muhammad’s successor, or
caliph, should be abU bakr (r. 632–634), one of
his closest companions and a respected member
of the community. However, a minority favored
Ali, Muhammad’s paternal cousin and son-in-law.
Ali’s backers became known as his shia (party
or faction), which is the basis of the English
term “Shiism.” They also became known as the
Alids. According to Shii accounts and the hadith,
shortly before his death Muhammad had identi-
fied Ali as the “master” (mawla) of those who had
also regarded Muhammad as their master. Even
though Ali became the caliph in 655, his reign
was troubled by civil wars and the strong opposi-
tion of the Umayyad clan of Mecca and Damas-
cus. Ali was assassinated by a disgruntled former
supporter, one of the khaWariJ, thereby setting a
pattern for martyrdom that would eventually pro-
foundly shape Shii thought and worship. Muslim
factions in the Hijaz and southern Iraq continued
to agitate for a male descendant of Muhammad’s
family to claim leadership of the umma, and a
number arose and were defeated. Foremost among
these was Ali’s son Husayn, who was killed by
Umayyad forces at karbala in southern Iraq in
680, together with most of his male supporters.
This event solidified martyrdom for a just cause
as a key component of Shii piety.
Another significant stage in the development of
Twelve-Imam Shiism occurred during the imam-
ate of JaaFar al-sadiq (ca. 699–765), the great-
grandson of Husayn. A highly respected scholar
in Medina, he lived when the Abbasid Revolu-
tion overturned the Umayyad caliphate and then
turned against Shii partisans who had been their
allies against the Umayyads. Jaafar was reportedly
imprisoned several times by the Abbasid caliph
al-Mansur (r. 754–775) and chose to distance him-
self from anti-Abbasid politics as a consequence.
Despite difficulties, he won a wide following as
both a scholar and a proponent of political quiet-
ism, which developed into the doctrine of taqiyya,
or pious concealment of one’s Shii beliefs in the
face of persecution or punishment. He has also
been credited with affirming his father Muham-
mad al-Baqir’s idea of nass, the divinely inspired
designation of an Imam by his predecessor, as a
way to resolve conflicting claims to Alid leader-
ship. To further enhance this idea and elevate
the Imams to a position as leading authorities in
matters of religion, the doctrine of the infallibil-
ity (isma) of the Imams was also asserted during
Jaafar’s time. Additionally, Shii tradition remem-
bers him as an expert in fiqh (jurisprudence).
Consequently, the Twelver tradition of law is
known as the Jaafari School. Succession to Jaafar
became confused when his designated heir, Ismail,
predeceased him in 755. Those remaining loyal to
Ismail recognized his infant son Muhammad asTwelve-Imam Shiism 677 J