funerary object of a chicken,
Kofun period. From the collection of the
Shibayama Haniwa Museum Early history Chiba Prefecture was settled in prehistoric times, as evidenced by the
Jōmon period remains in every part of the region. The prefecture holds the largest
kaizuka sea shell mounds in Japan, evidence of a large population in the prefecture that relied on the rich marine products of the Pacific Ocean and Tokyo Bay.
Kofun burial mounds are found across the prefecture, with the largest group being in Futtsu along Tokyo Bay.
Asuka and Nara periods In the
Asuka period (538–710), under the
Taika Reform of 645, the administrative structure of present-day Chiba Prefecture changed significantly. The historical province of
Fusa Province, which may have covered much of Chiba and
Ibaraki prefectures, was divided into two provinces:
Shimōsa Province (also called Shimofusa) in the north and
Kazusa Province in the southern area.
Awa Province at the south of Chiba Prefecture, was separated from Kazusa Prefecture in 718. These administrative units existed until they were abolished and merged into Chiba Prefecture after the
Meiji Restoration. The central government established a
kokubunji provincial temple in each province.
Heian period The imperial court gradually extended its authority over the three provinces in the
Nara (710–794) and
Heian (794–1185) periods.
Shōen feudal estates were established across the three provinces, and the region became an important source of tax revenue, sending agricultural and other products to the capital in Kyoto. As the Heian period progressed, however, the
kokushi provincial governors came to exert military power independent of the central government in Kyoto. The
Chiba clan broke entirely with the imperial court and was instrumental in the establishment of the
Kamakura shogunate.
Modern period training on
Kujūkuri Beach, early 1945 Chiba Prefecture was established on June 15, 1873, with the merger of
Kisarazu Prefecture and
Inba Prefecture. The
militarization of Chiba Prefecture dates to the
Russo-Japanese War (1904–1905). Coastal fortifications were built along
Tokyo Bay, as far south as Tateyama, to protect the capital of the
Empire of Japan from attack. In September 1923, the
Great Kanto earthquake has cause of widespread destruction in Chiba Prefecture, most notably in the southernmost part of
Boso Peninsula, where 1,300 residents were killed, out of 142,000 deaths. Areas of prefecture adjacent to Tokyo saw much damage, and mob violence against Koreans and other ethnic minorities occurred in the chaos after the earthquake in Funabashi,
Ichikawa, and other areas. Koreans, in several neighborhoods of Yachiyo, were killed, and a tower was erected in 1972 near
Yachiyodai Station to memorialize those killed in the incident. In the 1930s, the north and central areas of the prefecture became a center of large-scale military production, and military bases and fortifications were constructed in most of the coastal areas of the prefecture. After the United States took control of
Saipan, the northern part of the prefecture (most notably the cities of Chiba and Chōshi) was
firebombed. Much of the industrialized north of the prefecture was destroyed.
Operation Coronet, one of two parts of
Operation Downfall, was the planned land invasion of Tokyo in March 1946 by the United States. Coronet planned
Kujūkuri Beach as one of two initial landing bases, the other being
Hiratsuka via
Sagami Bay. The
U.S. First Army would enter at Kujūkuri, sweep across the Boso Peninsula, and meet the
U.S. Eighth Army at Tokyo. The plan was not carried out since
Japan surrendered after the
atomic bombings of Hiroshima and Nagasaki. During the
Occupation of Japan (1945–1952) Chiba Prefecture was controlled by American forces from the second floor of the prefectural capitol building in the city of Chiba. Numerous other cities in the prefecture, including Chōshi to the north and Tateyama to the south, were used as bases of the occupation; rich agricultural areas across the prefecture somewhat safeguarded the region's population from potential food shortages, and starvation, immediately following the war. The immediate post-war period was characterized by carefully planned industrial expansion in the north of the prefecture, and the significant increase of agriculture after
land reforms across the prefecture. The
Keiyō Industrial Zone brought together smaller, industrial areas along the entirety of the western coast of Chiba Prefecture, and the industrial zone became (and remains) an important center of heavy industrial production and large-scale port facilities in Japan. Cities to the northeast of the prefecture (in close proximity to Tokyo) were connected by rail to the capitol, and became and remain
bedroom communities to Tokyo.
Narita International Airport began operation in 1978 in
Narita, after much protest to replace the overcrowded
Tokyo International Airport (Haneda Airport). The majority of international air traffic enters Japan via Chiba Prefecture. The cultivation of
rice and vegetables to feed the
Greater Tokyo Metropolitan Area expanded greatly and became a source of income to the northeast and central areas of the prefecture. The expansion of agriculture in the central and southern regions of the prefecture was in contrast to the depopulation of these areas as a significant part of the population moved to the northeast of the prefecture as a result of the
urbanization of Japan, a process that continues into the 21st century. On March 11, 2011, the epicenter of
9.0 magnitude earthquake and tsunami and subsequent
Fukushima nuclear disaster that devastated much of the northeastern coast of Honshu, which caused some damage and affected areas in Chiba Prefecture. While the loss of life and damage to housing and industry was far less than in
Tōhoku region, 20 people were killed in Chiba Prefecture, including 13 people were recorded deaths in
Asahi. Following the triple disaster, an
oil refinery fire broke out at the
Cosmo Oil Chiba Refinery, in
Ichihara, and was widely covered in the news media. Also, a large
liquefied petroleum gas (LPG) tanks burned at 10 days earlier.
Soil liquefaction, in areas of
reclaimed land across the northern and western areas of Chiba Prefecture, caused damage to housing.
Chiba City,
Funabashi,
Narashino, and especially
Urayasu were greatly affected by triple disaster (such as soil liquefaction, and evidence of radioactive materials caused by the Fukushima radiation). As a result of triple disaster and with permanent damage to housing stock, the population of Chiba Prefecture fell for the first time since
Spanish flu pandemic in 1918 and
Great Kanto earthquake in 1923. == Geography ==