Joseph Sembratovych was born on 8 November 1821, son of a priest of the Archeparchy of Przemyśl.

Returned to Galicia, he started his career in the Seminary of Lviv, moving later in 1852 to Wien where he was appointed vice-rector of the Greek Seminary, and later he appointed Professor of Biblical Studies in the University of Lviv.

On 18 May 1870 Joseph Sembratovych was designated Metropolitan of Lviv, i.e. the primate of the Ukrainian Greek Catholic Church, by Emperor Franz Joseph I of Austria and so confirmed by Pope Pius IX on 27 June 1870.

[3] Even if before his appointment as Primate Joseph Sembratovych was supported by the Polish Galicians and unpopular with the Ukrainophils and the Ukrainian Russophiles, Joseph Sembratovych during his reign fully espoused the Russophile movement on a level which collided with Ukrainophil politic of the Austria-Hungary government.

The case that finally led to his resignation was the affair of Ivan Naumovich, a priest who favored the conversion of a whole village to the Russian Orthodox Church.