Stojan was born in ca. 1636, somewhere in the mountainous Bukovica region in North Dalmatia, modern-day Croatia, presumably in the village of Žegar, or Zelengrad. The village itself lied above the Žegar field, from where the population had long jumped into (i.e. guerilla warfare) the Dinara, the Venetian-Ottoman border for centuries. His father was harambaša Janko Mitrović (1613-1659), another renowned anti-Ottoman rebel in Venetian service, noted commander of the Morlach army in the Cretan War (1645-1669). Stojan had two brothers (Ilija and Zaviša Janković) and a sister Ana. The family of Stojan Janković belonged to Serb Orthodox community and their family slava was Đurđevdan.