Complex sentence: Unlike the Saxons, the Székelys did not receive a royal diploma which summarized their liberties, but they preserved their specific status, forming a "well organised community of warriors living off cattle breeding" for centuries.
Split into simpler sentences: Unlike the Saxons, the Székelys did not receive a royal diploma which summarized their liberties. Nevertheless, they preserved their specific status, forming a "well organised community of warriors living off cattle breeding" for centuries.