After Joffrey Baratheon’s assassination, Margaery married the former king’s much kinder, younger, and naiver brother, Tommen. Margaery easily manipulated Tommen, but Tommen’s mother, Cersei Lannister, eventually kills her, prompting Tommen to leap off a tower to his death — so it would appear Margaery’s manipulative tactics weren’t worth it in the end.