Koshi Province (越国, Koshi no Kuni) was an ancient province of Japan and is listed as one of the original provinces in the Nihon Shoki.[2] The region as a whole was sometimes referred to as Esshū (越州). In 701 AD, per the reforms of the Taihō Code, Koshi was divided into three separate provinces: Echizen, Etchū, and Echigo.
In 823 AD, the two eastern districts of Echizen Province (Kaga and Enuma) were separated to form Kaga Province. Kaga was thus the last province to be created under the ritsuryō system. The same year, the northern portion of Enuma District became Nomi District, and the southern portion on Kaga District became Ishikawa District. Kaga District itself was renamed Kahoku District.
The provincial capital and provincial temple were located in what is now the city of Komatsu; however, there does not appear to have been a provincial nunnery. The Ichinomiya of the province is the Shirayama Hime Shrine in what is now the city of Hakusan. Under the Engishiki classification system, Kaga was ranked as a "superior country" (上国) in terms of importance and "middle country" (中国) in terms of distance from the capital. Despite this classification, Kaga never developed a powerful local gōzoku clan but was divided into many shōen estates.
Following the Meiji Restoration and the abolition of the han system in 1871, Kaga Province was divided into Kanazawa Prefecture and Daishōji Prefecture, which were merged with Fukui Prefecture. However, only a few months later in 1872, Kanazawa and Daishōji were divided back out and merged with Nanao Prefecture (the former Noto Province) to form today's Ishikawa Prefecture. In 1876, former Etchū Province was united with Ishikawa, only to become separated again in 1883.[3]