Les XIe et XIIe siècles correspondent à une période durant laquelle l'orthodoxie sunnite a construit ses bases tant intellectuelles qu'institutionnelles. A cette époque où le Califat est affaibli, les Turcs Seldjoukides, en combinant l'habileté au combat des tribus turques et la tradition étatique de l'Iran, ont construit un état fort et assumé le leadership dans l'institutionnalisation du sunnisme. De manière générale, l'un des éléments saillants permettant de déterminer cette période est le fait que l'orthodoxie sunnite, qui s'institutionnalise en s'opposant fondamentalement au mutazilisme et au chiisme ou plutôt à l'une des branches du chiisme, l'ismailisme, intègre en son sein le mouvement soufi (taṣawwuf). Les personnalités mises en avant comme représentantes de cette période sont sur le plan intellectuel Ğuwaynī et Ġazālī et sur le plan politique le grand vizir seldjoukide Niẓām al-Mulk. Les Madrasas Niẓāmiyyas qui constituent l'un des traits concrets de l'institutionnalisation de l'orthodoxie sunnite, sont pour la plupart des réalisations de Niẓām al-Mulk. Celui-ci a réussi à transmettre aux générations suivantes ses réflexions sur le gouvernement de l'état et son administration grâce à son œuvre intitulée Siyāsat-nāma. / The eleventh and twelfth centuries correspond to a period during which Sunni orthodoxy built its intellectual and institutional foundations. At this time when the Khalifa was weakened, the Seljuk Turks, combining the fighting skills of the Turkish tribes and the state tradition of Iran, built a strong state and assumed leadership in the institutionalization of Sunnism. In a general way, one of the salient elements for determining this period is the fact that Sunni orthodoxy, which is institutionalized by fundamentally opposing mutazilism and Shiism or rather one of the branches of Shiism, Ismailism, integrates within it the Sufi movement. The personalities put forward as representatives of this period are on the intellectual plane Ğuwaynī and Ġazālī and politically the Grand Vizier Seljuk Niẓām al-Mulk. The Niẓāmiyyas Madrasas, which constitute one of the concrete features of the institutionalization of Sunni orthodoxy, are for the most part achievements of Niẓām al-Mulk. He managed to pass on his reflections on the state government and its administration to the following generations through his work entitled Siyāsat-nāma. / XIe et XIIe siècles ler sunnite ortodoksinin hem düşünsel hem de kurumsal temelde kurulduğu bir dönemdir. Hilafetin zayıfladığı bu zaman diliminde Türkler Seldjoukides göçebe Türk boylarının savaş yeteneklerini İran devlet geleneğiyle birleştirerek güçlü bir devlet kurmuş ve sunnite ortodoksinin kurumlaşmasında siyasal öncülüğü üstlenmişlerdir. Genel olarak chiisme ama daha çok da chiismin bir kolu olan ismāʿīlisme ve mutazilisme karşıtlığı temelinde kendini kurumsallaştıran sunnite ortodoksinin, taṣawwuf hareketini kendi içine çekmesi bu sürecin karakterini belirleyen en önemli olaylardan birisidir. Düşünsel planda Ğuwaynī ve Ġazālī, politik planda da daha çok Seldjoukides lerin büyük veziri Niẓām al-Mulk dönemin simge isimleri olarak öne çıkmışlardır. Sunnite ortodoksinin kurumlaşmasının en somut göstergelerinden biri olan Madrasas Niẓāmiyyas lar büyük oranda Niẓām al-Mulk ün bir eseridir. Niẓām al-Mulk, yazdığı Siyāsat-nāma isimli kitapla devlet yönetimi hakkındaki düşüncelerini gelecek kuşaklara aktarmayı başarmıştır.

Appelé à traduire conjointement les exigences conceptuelles d’une orthodoxie sunnite qui s’est désignée comme le dépositaire de la Vérité monothéiste, les exigences identitaires d’une Ûmma islamique soucieuse de s’inscrire au sein de l’évolution monothéiste de l’humanité et les revendications d’une institution califale préoccupée à consolider sa légitimité "précaire", le fiqh se présente sous la plume des auteurs musulmans comme un canevas idéel, authentique et sacralisé. Ainsi, considéré comme le support architecte d’al-Ûmma, le droit musulman n’allait pas seulement se détacher de de ses origines préislamique, et notamment celles qui seraient dues à une Rome érigée en symbole de l’égarement monothéiste, il allait également échapper aux principes, jugés faillibles, de la raison humaine et s’accommoder au référentiel mythologisé de la pensée qui l’a établi. / Called to translate jointly the abstract requirements of a Sunni orthodoxy which introduced itself as theagent of the monotheist Truth, the identical requirements of an Islamic Ûmma worried of joining within the monotheist evolution of the humanity and the claiming of a califale institution worried to strengthen its "precarious" legitimacy, the fiqh appears under the feather of the Muslim authors as an authentic and sacred pattern. So, considered as the support of the Ûmma, the Islamic law was not only going to give up its preislamic origins, and particularly those who would be due in Rome, set up as symbol of the monotheist wrongness; it was also going to escape the principles of the human reason and adapt the mythical reference of the thought who established it. By the analyzing of the Rome’s idea through the papers of the medieval fûqaha, this study tries to read the islamic law through its effective historicity and to understand the various factor and the circumstances which built it.