旅順攻囲戦
The Type 45 was developed after the Russo-Japanese War showed the value of heavy caliber howitzers and mortars when attacking strongly fortified enemy positions. The heavy weapons used by the Japanese Army at the Siege of Port Arthur were 28cm Imperial Japanese army howitzers. The Type 45 was the first such weapon designed and built entirely in Japan, and entered service in 1912. It was usually deployed as part of coastal artillery batteries.