Complex sentence: Although Petrescu showed himself to be staunchly against Hungarian nationalism, his wife may have been of Hungarian origin--allegedly, he had her adopted by an impoverished count in Trieste, as a means for the family to inherit a formal title.
Split into simpler sentences: Although Petrescu showed himself to be staunchly against Hungarian nationalism, his wife was of Hungarian origin. Allegedly, he had her adopted by an impoverished count in Trieste, as a means for the family to inherit a formal title.