Complex sentence: The marriage was a political gesture and many believe there was little love between Nōhime and Nobunaga; she was the official wife of Oda Nobunaga although it is often believed that he focused his love on his concubine Kitsuno, who bore him his son Nobutada.
Split into simpler sentences: The marriage was a political gesture and many believe there was little love between Nōhime and Nobunaga. Nōhime was the official wife of Oda Nobunaga although it is often believed that he focused his love on his concubine Kitsuno, who bore him his son Nobutada.