Complex sentence: If he was identical to king Wadjenes he ruled-according to the Royal Canon of Turin-for 54 years, if Weneg was identical to a king "Tlas", mentioned by the ancient greek historian Manetho, he ruled for 17 years.
Split into simpler sentences: If he was the same person as king Wadjenes, he ruled (according to the Royal Canon of Turin) for 54 years. If Weneg was same person as king "Tlas", mentioned by the historian Manetho, he ruled for 17 years.