Old Polish dithematic given names of Slavic origin of the type 'Boguchwal', 'Czcibor', 'Domarad', 'Kazimierz', used in the Middle Ages, fell out of use to a significant extent during the Middle Polish period (16th-18th centuries), and were almost forgotten, in favor of borrowed Christian names. In the 19th century efforts were made to bring these native names, extracted from old documents, back to life and to give them to children, out of patriotic motives, with the intention of preserving the national identity after the loss of Poland's independence. The article presents the history of the ancient dithematic given names' return, and particularly their presence in the set of first names given in Poland in the 20th century, showing traditional forms as well as innovations and even false and corrupted readings of the names.