The entrepreneurial family Tönnies was present in Slovenia for almost a century, from the middle of the 19th to the middle of the 20th century. With its work, the construction of various buildings especialy, family permanently marked the space, physical and social. As entrepreneurs, they were heavily involved in the economic and social environment of Carniola, and later in Slovenia. The Tönnies family can be considered as the pioneers of economic modernization in second half of 19. Century. The authors systematically analyze their economic performance, corporate strategies and risk management practices and accumulation of capital, social networks, and relations with the political sphere in the age of nationalism. The family life styles and practices, the structure of families and households of individual family members are discussed as well. This is a rare example of a comprehensive presentation of the entrepreneurial path of one of the economically and socially important families in the context of the economic, political and social development stages of Slovenian society up to the Second World War.