 They were one of the most economically active families who helped to create an industrial revolution in Slovenian towns and cities and made a significant contribution to the historical records which include the fact that the land of Carniola was ranked as one of the most developed European provinces and which also influenced the development of the cities of Trieste, Sarajevo and Zagreb.Gustav Tönnies was born in Sweden, where he studied carpentry and worked as an apprentice in several European cities.In 1845, he was sent from Graz to Ljubljana to work on the construction of the roof of Kolizej, at the time one of the largest buildings in this part of Europe.