Hard pressed in Europe, where she had only a narrow margin of superiority against Germany, Britain had requested, but was denied, the loan of Japan's four newly-built Kongō-class battlecruisers (Ship Japanese battleship Kongō 2 , Ship Japanese battleship Hiei 2 , Ship Japanese battleship Haruna 2 , and Ship Japanese battleship Kirishima 2 ), some of the first ships in the world to be equipped with 356 mm guns, and the most formidable battlecruisers in the world at the time.