At the beginning of the 19th century began a new phase in the history of Azerbaijan. The conquest of this region solved the balance of power in the traditionally Russian-Turkish-Iranian standoff. Began a planned takeover and the Division of the historical territories of Azerbaijani lands along the Araz river resulting in the Northern Khanate was annexed to Russia, and southern remained a part of the Shah’s Iran. Since this period, the administrative structure, as well as the architecture and culture of separated territories, inhabited by a people gets a different development. In the first quarter of the 19th century in Northern Azerbaijan military authorities began topographic fixing of the existing settlements on the ground. The main architectural and construction activities were carried out by military engineers directly engaged in construction of fortifications and their preparations for defense. Thus arose Zagatala, Gakh, Gusar fortresses on the basis of which were later established the towns. To strengthen borders the Tsarist Government resettled here Christian peoples who created new settlements and characteristic itself cultural environment, which in turn was reflected in the regional architecture of 19th and beginning of 20th centuries. Important for the future development of settlements was the activity engineers, architects, scientists, historians, artists coming from Russia who had studied the situation of historical cities and buildings of the region. Self-made urbanistic plans, measurements of monuments, articles, recordings and drawings became important sources for further research in this area. It should be noted that during this period clearly manifest themselves formed for centuries and enriched with new technology traditions of architectural heritage. Original constructive schemes, design patterns, shapes and architectural and decorative elements of buildings, developed over the centuries due to the mined out experience skillfully preserved and applied in the construction of various character of buildings in the regions of Azerbaijan. National architectural trends had been clearly reflected in the works of the prominent Azerbaijani architects, architects and craftsmen who left deep traces in our heritage. Despite annexation of Azerbaijani lands and rigid colonial policies of Tsarism, the process of acceding of North Azerbaijan to Russia and also played historically progressive role in its development. The continuous internecine wars between khans ended and began abolished feudal division establishing of new economic and cultural development began. This period in the development of architecture and construction of the country, despite the difficult political circumstances, was the underlying cause for further economic growth and urban development of modern Azerbaijan. In the new socio-economic conditions broke the old principles of urban planning, new techniques for urban development, and new types of public, civil, industrial, and religious buildings revealed. With the growth and changing composition of the population there has been interference with traditional and new imported Western culture. The historical heritage of the period of the 19th - beginning of the 20th centuries, has today a great importance in the forming of architecture of the cities of modern Azerbaijan.