Thessaloniki, until its liberation in 1912, was the most significant city in the Balkans and one of the two or three most important cities of the Ottoman Empire. Its importance stemmed from its geopolitical position and its economic power, as it almost entirely controlled the export and import trade of the Balkans.

From the late 17th century, the Great Powers of the time recognized this significance and established consulates, which by the end of the 19th century numbered 25; an impressive figure, slightly fewer than the number of embassies in Constantinople.

The heads of consulates or vice consuls who served in the city over 225 years numbered around 300. Their primary role until the early 19th century was to promote the trade of their nations.

Subsequently, their diplomatic role was elevated, as political upheavals in Europe increased their influence in the declining Ottoman Empire. The consuls and their families positively influenced the social and cultural development of the city.

The information in this book mainly comes from communication with the Foreign Ministries and state archives of the countries and principalities.