One reason, as Badger rightly remarks, the Yezidis so designate the place for the sake of brevity, is the entablature over the doorway records the name in full, “Sheikh Shams Ali Beg and Faris.” Two persons are mentioned in the inscription.[153] In like manner, the word Šams frequently enters into the construction of Mohammedan names. The most celebrated one that bore this name was Šams ud-Din of Tabriz, the friend and spiritual guide of Jalal ad-Din, who flourished during the first half of the 13th century of our era. Moreover, round about the tomb of Šeiḫ ‘Adi are many such abandoned shrines, each of which is dedicated to a similar deified šeiḫ. Many of these šeiḫs are known to be historical personages. Take for example, Šeiḫ ‘Abd al-ḳadir of Gilan. He is Šeiḫ Muḥiyy ud Din ‘Abd al ḳadir of Gilan in Persia, the founder of the ḳadiri order of dervishes. He was born in A. H. 471 (A. D. 1078-9) and died A. H. 516 (A. D. 1164-5). So also Šeiḫ ḳaḍib al-Ban. He was from Mosul, and was a contemporary of Šeiḫ ‘Adi. In giving the life of Muḥi ad Din aš-Šharnozuri, Ibn Ḫallikan (v. 2,651) says, “His corpse was removed to a mausoleum built for its reception outside the Maidan Gate of Mosul, near the tomb of ḳadib al-Ban, the celebrated worker of miracles.” Further, Manṣur al-Ḥallaj was a celebrated mystic, revered as a saint by the more advanced sufis. He was put to death with great cruelty at Bagdad in A. H. 309 (A. D. 921-2) on a charge of heresy and blasphemy, because he had said in one of his ecstacies, “Ana-l-Ḥaḳḳ, I am the truth, God.” All biographers of sufi saints speak of him with admiration. There are still others who are mentioned even among the seven šeiḫs enumerated in the principal prayer. Šeiḫ Ḥasan (written also Šeiḫisin) was from Baṣrah. He was a celebrated theologian and died in A. D. 728. His life is given by Ibn Ḫallikan. He was noted for self-mortification, fear of God and devotion. And Faḫr ad-Din is ibn Abd Allah Mohammed Ibn Amar al-Ḥuṣain Ibn al-Ḥasan, Ibn ‘Ali Al-Taim al-Bakri al-Taberstani ar-kai-zi (native of Kai in Tabarestan), surnamed Faḫr ad-Din (glory of faith). He was a doctor of the Shafite sect, a pearl of his age, a man without a peer. He surpassed all his contemporaries in scholastic theology, and preached both in Arabic and Persian. He would draw floods of tears from his eyes. His virtues and merits were boundless. He was born at Kai, 25th of Ramadan, A. H. 544 (A. D. 1150), and died at Ḥerat, the first of Shawal, A. H. 606 (March A. D. 1210). (See ibn Ḫallikan in loco.) In the light of these facts, I conclude, then, that those who cannot be identified—for many bear the same name, and we do not know which is which—are also historical personages. This is what I mean by the statement that in order to yield satisfactory results the inductive method must be supported by historical investigations.