He was born in what is now Croatia. However, his parents were Serbs so his native language was Serbian. At the time that he was born (1856) the area where he was born was part of the empire of Austria-Hungary.
He was born in July 1856, Similian village, commune Gospici province Lica (on the shore of the Adriatic), a compact village inhabited by Istro-Romanians. Teslea was a nick-name of his father, from the basic tool of the carpenter , a tradition for the Istro-Romanian family of his mother .