Illyrio is a magister in Pentos, a free city on the continent of Essos, which is east of Westeros across the Narrow Sea. Illyrio provides help and shelter to and when they are in Pentos with the expectation that he’ll be rewarded if Viserys reclaims the Crown. As a wedding gift, he gives Daenerys three petrified dragon eggs. Daenerys later performs a spell that leads dragons to hatch from those eggs.