Abstract
This is the first part of the article that pursues a part of a social network of Sylvie Kateřina Černínová, born Caretto of Milessimo (1606-1664). Most important of used sources is edition of Sylvia’s correspondence with her husband Heřman Černín from Chudenice (1576-1651).
In the centre of attention (of this first part) is the family she originated. The close relationship of Sylvie with her sister Olympia is evident especially during the preparation of her sister's wedding with Filip count of Magni.
The end of the works deals with the marriage of Heřman count Czernin with Sylvia Kateřina. There are analyzed the reasons for their wedding: the main reasons were probably symbolical capital that Heřman obtained by marrying a woman from such a noble house and the fertile age of Sylvia Katarin - he had from two previous marriages any child.