The Aizu Domain was a historical feudal domain in Japan, located in the present-day Fukushima Prefecture. It was established during the Edo period and was ruled by the Matsudaira clan. The domain was known for its strong samurai culture and played a significant role during the Boshin War. Aizu was notable for its resistance against the imperial forces during the conflict, particularly at the Tsuruga Castle. The domain's loyalty to the Tokugawa shogunate made it a focal point in the struggle between traditional samurai values and the modernization of Japan.