He was born Ioann Kuntsevych in 1580 or 1584 in Volodymyr, Volhynian Voivodeship, in the Lesser Poland Province of the Polish Crown (now in Ukraine).
Ia lahir dengan nama Ioann Kuntsevych pada 1580 atau 1584 di Volodymyr, Kevoivodesipan Volhynian, di Provinsi Polandia Kecil dari Mahkota Polandia (sekarang di Ukraina).