The town of Mashad, the present capital of Khorasan, has supplanted the older city and district of Tus, which was an ancient capital. The ruins of this city lie fifteen miles to the northwest. As early as the tenth century we have references to the birthplace of Al-Ghazali. Thus Misʾar Muhalhil (about 941 A. D.) writes: “Tus is made up of the union of four towns, two of which are large and the other two of minor importance; its area is a square mile. It has beautiful monuments that date from the time of Islam, such as the house of Hamid, son of Kahtabah, the tomb of Ali, son of Musa, and that of Rashid in the environs (lit. gardens) of the town.” Istakhri (951 A. D.), writing ten years later, speaks of Tus as a dependency with four large towns or settlements. He says: “Taking Tus as a dependency of the province of Nishapur, its towns are Radkan, Tabaran, Bazdghur, and Naukan, in which (latter) is the tomb of Ali, son of Musa ar-Riza (may the peace of God be upon him), and the tomb of Haroun ar-Rashîd.... The tomb of Ar-Riza is about one-quarter of a _farsakh_ distant towards the village called Sanabadh.” The best summary of the history of Tus and description of its present condition is given by Professor A. V. Williams Jackson in his most interesting book, “From Constantinople to the Home of Omar Khayyam.” He tells us that the name of the town is as old as the half-legendary warrior Tusa of the Avesta, who gave battle against Turan. Alexander the Great passed through it in pursuit of Bessus, the slayer of the last Darius. During the Zoroastrian sway, the city of Tus shared with Nishapur the distinction of being the seat of a Nestorian Christian bishop. When the Arab conquest of Persia came Tus fell before the invaders and it became a great Moslem centre, famous especially as the home of the poet Firdausi, who was born there about 935 A. D. and died 1025 A. D.