So Long a Letter is an epistolary novel written by Senegalese author Mariama Bâ, where the main character, Ramatoulaye, writes letters to her late husband's first wife, Aissatou. The novel explores themes of polygamy, colonialism, and women's liberation in a post-colonial society. The story is framed by Ramatoulaye’s grief over the loss of her husband, Modou, and the events surrounding his death, but it also details her own personal struggles and those of her children. Through her letters, Ramatoulaye reveals the complexities of her own marriage, the societal pressures she faces as a woman in Senegal, and the challenges of navigating a changing world.