Recently it has been assumed that Archbishop Jakub of Gniezno was behind this testament, because he was in Wrocław on 17 June 1290, a few days before the death of Henryk IV.
Baru-baru ini dianggap bahwa Uskup Agung Jakub dari Gniezno berada di balik surat wasiat ini, karena ia berada di Wrocław pada tanggal 17 Juni 1290, beberapa hari sebelum kematian Henryk IV.