A samurai's daughter's greatest duty was political marriage. These women married members of enemy clans of their families to form a diplomatic relationship. These alliances were stages for many intrigues, wars and tragedies throughout Japanese history. A woman could divorce her husband if he did not treat her well and also if he was a traitor to his wife's family. A famous case was that of Oda Tokuhime (Daughter of Oda Nobunaga); irritated by the antics of her mother-in-law, Lady Tsukiyama (the wife of Tokugawa Ieyasu), she was able to get Lady Tsukiyama arrested on suspicion of communicating with the Takeda clan (then a great enemy of Nobunaga and the Oda clan). Ieyasu also arrested his own son, Matsudaira Nobuyasu, who was Tokuhime's husband, because Nobuyasu was close to his mother Lady Tsukiyama. To assuage his ally Nobunaga, Ieyasu had Lady Tsukiyama executed in 1579 and that same year ordered his son to commit seppuku to prevent him from seeking revenge for the death of his mother.