Complex sentence: Empress Maria Theresa had signed the treaty to gain time to rebuild her military forces and forge new alliances; she intended to regain her ascendancy in the Holy Roman Empire and to reacquire Silesia.
Split into simpler sentences: Empress Maria Theresa had signed the treaty to gain time to rebuild her military forces and forge new alliances. She intended to regain her ascendancy in the Holy Roman Empire and to reacquire Silesia.