Bukhara, one of the oldest cities in Central Asia, was already a town in the first millennium BC, it became important historically in the eigth century, when it was conquered by the Arab Abbasid Caliphate (709 AD/90 AH). Bukhara flourished both intellectually and commercially, and by the tenth century, under the powerful Samanid Dynasty, it became a renowned center of the arts and learning, especially the sciences and mathematics. The city's rich cultural heritage, commissioned by the patronage of its rulers, includes many architectural landmarks of the Islamic world. Recent excavations by the Uzbek Academy of Sciences have revealed that present day Bukhara is built up on layers of past settlements. By dating some of the discovered remnants that have been excavated, it is quite likely that Bukhara can be considered at least 2,500 years old.
Bukhara lies on a flat plain and is surrounded by semi-desert lands. It is situated on the edge of the Kizilkum desert and has a dry and arid climate. In the past, the Bukhara oasis formed part of a vast region of Central Asia which had been conquered by Alexander of Macedon. These events led to the forming of feudalism in the Bukharan oasis.
The new social system introduced a social hierarchy: the individual principalities were ruled by kings supported by armed nobility. The process of town formation became very active and the ancient settlements surrounding Bukhara developed into the towns of Varakhsha, Vardanzi, Ramish, and Kermine. All these towns followed a similar structural pattern, they all were made up of: the Ark (citadel), the Shakhristan -well planned residential; core, and a necropolis on the outskirts of the city.
Bukhara in this period followed the same layout and pattern of development. It sprawled over an area of forty hectares. The Shakhristan which was rectangular was cut into four sections by two crossing main streets which led to gates opening out on all four sides of the city. At the turn of the tenth century, Bukhara had developed into a major cultural and religious center. Bukhara was almost leveled by Gengis Khan in 1226/623 AH; few monuments survived the destructiveness of the Mongol hordes. Bukhara revived under the Shaybanid Dynasty in the sixteenth century, but it's importance decreased with the decline in traffic along the Silk Road. In 1753/1166 AH, Bukhara became an independent emirate and remained so until 1868/1285 AH, when it was incorporated as a vassal state under Tsarist Russia. Bukhara was forcefully taken by the Bolshevik forces after WWI; a number of monuments suffered great destruction during the bombardment.
Nekrasova, E. G. 1999. Lower Layers of Bukhara: Characteristics of the Earliest Settlements. In Bukhara: The Myth and the Architecture. Attilio Petruccioli (ed). Cambridge, Massachusetts: Aga Khan Program for Islamic Architecture.