Vakhnianyn was born in Sieniawa, Przeworsk County, today a part of Poland but at that time a part of the Austrian Empire.
The central area of the line around Jarosław (between Radymno and Sieniawa was manned by four battalions of infantry and 20 guns under the command of Lieutenant-Colonel Jan Wójcik of the 2nd Legions' Infantry Division.
In October 1944 these were joined by a further transfer of Lubaczów, Horyniec, Laszki, Uhnów and Sieniawa raions of the Lviv Oblast from the Ukrainian Soviet Socialist Republic.