British people brought curry from the Indian colony back to Britain and introduced it to Japan during the Meiji period (1868 to 1912), after Japan ended its policy of national self-isolation ("sakoku"), and curry in Japan was categorised as a Western dish. Its spread across the country is commonly attributed to its use in the Japanese Army and Navy which adopted it extensively as convenient field and naval canteen cooking, allowing even conscripts from the remotest countryside to experience the dish. The Japan Maritime Self-Defense Force traditionally have curry every Friday for lunch and many ships have their own unique recipes.