Mergers from April 1, 1999 to Present

• On April 1, 2001 - the town of Shiroi
  Shiroi, Chiba
  is a city located in northern Chiba Prefecture, Japan. As of late March 2011, the city has an estimated population of 61,073 and a population density of 1725 persons per km²...
  
  from Inba District
  Inba District, Chiba
  is a district located in Chiba, Japan.As of 2011, the district has an estimated population of 43,480 and a density of 845 persons per km². The total area is 51.48 km².There are two towns within the district.*Sakae*Shisui-District timeline:...
  
   was promoted to city status.

• On April 1, 2002 - the town of Tomisato
  Tomisato, Chiba
  is a city located in northeastern Chiba Prefecture, Japan. As of February 2011, the town had an estimated population of 50,886 and a population density of 944 persons per km²...
  
  from Inba District
  Inba District, Chiba
  is a district located in Chiba, Japan.As of 2011, the district has an estimated population of 43,480 and a density of 845 persons per km². The total area is 51.48 km².There are two towns within the district.*Sakae*Shisui-District timeline:...
  
   was promoted to city status.

• On June 6, 2003 - The city of Noda
  Noda, Chiba
  is a city located in the far northwestern corner Chiba Prefecture, Japan. As of February 2011, the city had an estimated population of 155,431 and a population density of 1500 persons per km²...
  
  absorbed the town of Sekiyado
  Sekiyado, Chiba
  was a town located in Higashikatsushika District, Chiba, Japan. Bordered by the Tone River and Ibaraki Prefectureto the east, and the Edo River and Saitama Prefecture on the west, it was formerly the northernmost municipality in Chiba Prefecture....
  
   from Higashikatsushika District
  Higashikatsushika District, Chiba
  was a district located in Chiba, Japan until March 27, 2005. On March 28, 2005 the district was dissolved when the town of Shōnan merged into the city of Kashiwa.-Area:...
  
  . (Merger information page)

• On February 11, 2005 - the old city of Kamogawa
  Kamogawa, Chiba
  is a city located in Chiba Prefecture, Japan.As of 2010, the city had an estimated population of 35,257 and a population density of 184 persons per km². The total area was 191.30 km²...
  
   merged with the town of Amatsukominato
  Amatsukominato, Chiba
  was a town located in Awa District, Chiba Prefecture, Japan.Amatsukominato was formed on February 11, 1955 by the merger of the towns of Amatsu and Kominato...
  
   to form the city of Kamogawa
  Kamogawa, Chiba
  is a city located in Chiba Prefecture, Japan.As of 2010, the city had an estimated population of 35,257 and a population density of 184 persons per km². The total area was 191.30 km²...
  
  .

• On March 28, 2005 - The city of Kashiwa
  Kashiwa, Chiba
  is a city located in northern Chiba Prefecture, Japan. As of February 2011, the city had an estimated population of 404,820 and a population density of 3520 persons per km²...
  
  absorbed the town of Shōnan
  Shonan, Chiba
  was a town located in Higashikatsushika District, Chiba Prefecture, Japan.On April 1, 1889 the villages of Kazahaya and Tega were established within the district of Minamisōma District, Chiba. On April 1, 1897, Minamisōma District merged with Higashikatsushika District. Shōnan Village was formed...
  
  . (Merger information page)

• On July 1, 2005 - The old city of Asahi
  Asahi, Chiba
  is a city located in northern Chiba, Japan. As of February 2011, the city had an estimated population of 69,000 and a population density of 531 persons per km². The total area was 129.91 km².-Geography:...
  
   and the towns of Hikata
  Hikata, Chiba
  was a town located in Katori District, Chiba Prefecture, Japan.Hikata was formed on April 10, 1954. through the merger of the villages of Kojo, Chowa, and Manzai...
  
  , Iioka
  Iioka, Chiba
  was a town located in Kaijō District, Chiba Prefecture, Japan.Iioka was a noted port town in the Edo period, and prospered greatly in the aftermath of the Great Fire of Meireki in 1657, as a transshipment center for timber and building materials to Edo....
  
  , and Unakami
  Unakami, Chiba
  was a town located in Kaijō District, Chiba Prefecture, Japan.Unikami was formed on March 31, 1954. through the merger of the villages of Takisato, Oumei, and Tsurumaki...
  
   merged to form the city of Asahi
  Asahi, Chiba
  is a city located in northern Chiba, Japan. As of February 2011, the city had an estimated population of 69,000 and a population density of 531 persons per km². The total area was 129.91 km².-Geography:...
  
  . (Merger information page)

• On December 5, 2005 - The towns of Isumi
  Isumi, Chiba
  is a city in Chiba Prefecture, Japan. As of March 1, 2010, the city has a population of 41,014 in an area of 157.50 km².Tōkyō Station is reached from Isumi by express train in 1 hour and 10 minutes via Ōhara Station on the JR East Sotobō Line.-Geography:...
  
  , Misaki
  Misaki, Chiba
  was a town located in Isumi District, Chiba Prefecture, Japan.Misaki was formed on August 1, 1961 by the merger of the towns of Chōjamachi and Taitō...
  
   and Ōhara
  Ohara, Chiba
  was a town located in Isumi District, Chiba Prefecture, Japan.Ōhara was formed on March 31, 1955 by the merger of the villages of Tōkai, Azuma and Namihana...
  
   merged to form the new city of Isumi
  Isumi, Chiba
  is a city in Chiba Prefecture, Japan. As of March 1, 2010, the city has a population of 41,014 in an area of 157.50 km².Tōkyō Station is reached from Isumi by express train in 1 hour and 10 minutes via Ōhara Station on the JR East Sotobō Line.-Geography:...
  
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• On January 23, 2006 - the city of Yōkaichiba
  Yokaichiba, Chiba
  was a city located in northeastern Chiba Prefecture, Japan.Fukuoka Town was established on April 1, 1889 within Sōsa District, Chiba. It changed its name to Yōkaichiba on December 8, 1915. On March 31, 1954, the town expanded greatly through the annexation of the neighboring villages of Heiwa,...
  
   and the town of Nosaka
  Nosaka, Chiba
  was a town located in Sōsa District Chiba Prefecture, Japan.Noda and Sakae villages were established on April 1, 1889 within Sōsa District, Chiba. The two villages merged on July 17, 1954 to form Nosaka Town....
  
   merged, forming the city of Sōsa
  Sosa, Chiba
  is a city located in northeastern Chiba Prefecture, Japan. As of February 2011, the town had an estimated population of 38,764 and a population density of 391 persons per km². The total area was 101.78 km².-Geography:...
  
  .

• On March 20, 2006 - The municipalities of Tomiura
  Tomiura, Chiba
  is a former town located in Awa District, Chiba, Japan. As of March 20, 2006, the town had an estimated population of 5,698 and a density of 221 persons per km². The total area was 25.69 km².-Geography:...
  
  , Tomiyama
  Tomiyama, Chiba
  is a former town located in Awa District, Chiba, Japan. As of March 20, 2006, the town had an estimated population of 5,841 and a density of 145 persons per km². The total area was 40.34 km².-Geography:...
  
  , Miyoshi
  Miyoshi, Chiba
  is a former village located in Awa District, Chiba, Japan. As of March 20, 2006, the village had an estimated population of 4,560 and a density of 135 persons per km². The total area was 33.92 km².-Geography:...
  
  , Shirahama
  Shirahama, Chiba
  is a former town located in Awa District, Chiba, Japan. As of October 1, 2004, the town had an estimated population of 6,027 and a density of 353 persons per km². The total area was 17.07 km².-Geography:...
  
  , Chikura
  Chikura, Chiba
  is a former town located in Awa District, Chiba, Japan. As of October 1, 2004, the town had an estimated population of 12,527 and a density of 342 persons per km². The total area was 36.64 km².-Geography:...
  
  , Maruyama
  Maruyama, Chiba
  is a former town located in Awa District, Chiba, Japan. As of August 1, 2004, the town had an estimated population of 5,780 and a density of 131 persons per km². The total area was 44.11 km².-Geography:...
  
   and Wada
  Wada, Chiba
  is a former town located in Awa District, Chiba, Japan. As of March 20, 2006, the town had an estimated population of 5,717 and a density of 176 persons per km². The total area was 32.45 km².-Geography:...
  
   merged, forming the city of Minamibōsō
  Minamiboso, Chiba
  is a city located in Chiba Prefecture, Japan. As of 2010 data, the city had an estimated population of 42,035 and a population density of 183 persons per km²...
  
  .

• On March 27, 2006 - The city of Narita
  Narita, Chiba
  is a city located in Chiba Prefecture, Japan. It is the site of Narita International Airport, the main international airport serving the Greater Tokyo Area....
  
  absorbed the towns of Shimofusa
  Shimofusa, Chiba
  was a town located in Katori District, Chiba Prefecture, Japan.During the Edo period, the area of present-day Shimofusa was part of Takaoka Domain, a minor feudal domain of the Tokugawa shogunate. Modern Namekawa Village was established on April 1, 1889...
  
   and Taiei
  Taiei, Chiba
  was a town located in Katori District, Chiba Prefecture, Japan.Taiei is located on Route 51 from Narita to Sawara. It has a very scenic country side with views of the Narita International Airport runways and aircraft. At Raikodai there is a large industrial estate.Modern Taiei Town was established...
  
  .

• On March 27, 2006 - The city of Sawara
  Sawara, Chiba
  was a city located in Katori District, Chiba Prefecture, Japan.Sawara has been settled since prehistoric times, and has numerous remains of Jōmon period shell middens and Kofun period burial mounds...
  
   and the towns of Omigawa
  Omigawa, Chiba
  was a town located in Katori District, Chiba Prefecture, Japan.Omigawa has been settled since prehistoric times, with numerous shell middens and burial mounds from the Japanese Paleolithic through Kofun period. During the Edo period, it was the center of Omigawa Domain, a feudal domain of the...
  
  , Yamada
  Yamada, Chiba
  was a town located in Katori District, Chiba Prefecture, Japan.Yamada Town was established on August 1, 1954 through the merger of town of Fuma with the villages of Yatsu and Yamakura...
  
   and Kurimoto
  Kurimoto, Chiba
  was a town located in Katori District, Chiba Prefecture, Japan.Kurimoto Village was established on April 1, 1889. It was raised to town status on April 10, 1924....
  
   merged, forming the city of Katori
  Katori, Chiba
  is a city located in northern Chiba, Japan. As of February 2011, the city had an estimated population of 82,633 and a population density of 315 persons per km². The total area was 262.31 km²...
  
  .

• On March 27, 2006 - The municipalities of Sanbu
  Sanbu, Chiba
  was a town located in Sanbu District, Chiba Prefecture, Japan.Sanbu Town was formed on March 1, 1955 through the merger of the villages of Mutsuoka and Hyūga. On March 27, 2006 Sanbu was merged with the towns of Matsuo and Narutō, and the village of Hasunuma, all from Sanbu District to form the...
  
  , Naruto
  Naruto, Chiba
  was a town located in Sanbu District, Chiba Prefecture, Japan.Narutō Town was established on April 1, 1889 within Musha District, Chiba. Musha District became part of Sanbu District from April 1, 1897. On October 1, 1954 Narutō expanded through the annexation of the neighboring villages of Ōtomi...
  
  , Hasunuma
  Hasunuma, Chiba
  was a village located in Sanbu District, Chiba Prefecture, Japan.Hasunuma Village was formed on April 1, 1889 within Musha District, Chiba. Musha District became part of Sanbu District from April 1, 1897...
  
   and Matsuo
  Matsuo, Chiba
  was a town located in Sanbu District, Chiba Prefecture, Japan.Matsuo Village was formed on April 1, 1889 within Musha District, Chiba. Musha District became part of Sanbu District from April 1, 1897. On August 31, 1898, Matsuo was raised to town status. It expanded through the annexation of the...
  
   merged to form the city of Sanmu
  Sanmu, Chiba
  is a city located in northeast Chiba Prefecture, Japan. As of September 2010, the city had an estimated population of 56,074 and a population density of 383 persons per km²...
  
  .

• On March 27, 2006 - The town of Hikari
  Hikari, Chiba
  was a town located in Sōsa District, Chiba, Japan.In 2003, the town had an estimated population of 12,055 and a density of 361.90 persons per km². The total area was 33.31 km²....
  
   from Sōsa District and the town of Yokoshiba
  Yokoshiba, Chiba
  was a town located in Sanbu District, Chiba Prefecture, Japan.Asahi Village was established on April 1, 1889 within Musha District, Chiba. It changed its name to Yokoshiba on December 28, 1892. Musha District became part of Sanbu District from April 1, 1897. On May 10, 1897, Yokoshiba was elevated...
  
   from Sanbu District
  Sanbu District, Chiba
  is a district located in Chiba, Japan.As of September 2010, the district had an estimated population of 100,954 and a population density of 525 persons per km²...
  
   merged, forming the town of Yokoshibahikari
  Yokoshibahikari, Chiba
  is a town located in Sanbu District, Chiba Prefecture, Japan. As of September 2010, the town had an estimated population of 24,913 and a population density of 372 persons per km². The total area was 66.91 km².-Geography:...
  
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• On March 23, 2010 - the old city of Inzai
  Inzai, Chiba
  is a city located in the north-west of Chiba Prefecture, Japan. As of late February 2011, the city has an estimated population of 88,652 and a population density of 716 persons/square kilometer. The total area was 128.80 km².-Geography:...
  
   merged with the villages of Inba
  Inba, Chiba
  was a village located in Inba District, Chiba, Japan.Inba Village was created on March 10, 1955 through the merger of Rokugo and Munakata Villages. The development of Chiba New Town greatly accelerated the development of the village, which became a bedroom community for Chiba...
  
   and Motono
  Motono, Chiba
  was a village located in Inba District, Chiba, Japan.Motono Village was created on April 1, 1914 through the merger of Hongo and Yawara Villages. The development of Chiba New Town greatly accelerated the development of the village, which became a bedroom community for Chiba. As of February 2011,...
  
   to form the city of Inzai
  Inzai, Chiba
  is a city located in the north-west of Chiba Prefecture, Japan. As of late February 2011, the city has an estimated population of 88,652 and a population density of 716 persons/square kilometer. The total area was 128.80 km².-Geography:...
  
  .