Region IV-A (CALABARZON)

PSGC: 040000000
ISO: 04
Regional Centre: Calamba, City of
Congressional Districts: 19
Provinces: 5
Cities: 12
Municipalities: 130
Barangays: 4,011

September 24, 1972: Region IV (Southern Tagalog) created from Aurora, Batangas, Cavite, Laguna, Marinduque, Occidental Mindoro, Oriental Mindoro, Palawan, Quezon, Rizal and Romblon with Quezon City as the regional centre, by Presidential Decree No. 1 as part of the Integrated Reorganisation Plan.
January 23, 1976: Region IV renamed to Region IV-A (Southern Tagalog) due to the creation of Region IV (Metropolitan Manila) by Presidential Decree No. 879. Later reverted back to Region IV (Southern Tagalog).
May 17, 2002: Region IV-A (CALABARZON) created from Region IV (Southern Tagalog) by Executive Order No. 103.
October 28, 2003: Calamba, City of, designated as the regional centre by Executive Order No. 246.

PSGC: 041000000
ISO: BTG
Province Capital: Batangas City
Area Code: 43
Congressional Districts: 4
Cities: 3
Municipalities: 31
Barangays: 1,078

1581: Batangas province created but originally called Bombon, Balayan or Comintan.
March 10, 1917: Province established by Act No. 2711.

PSGC: 042100000
ISO: CAV
Province Capital: Trece Martires City *
Area Code: 46
Congressional Districts: 3
Cities: 3
Municipalities: 20
Barangays: 829

1614: Cavite province created.
March 10, 1917: Province established by Act No. 2711.

* Trece Martires City is the seat of the provincial government but Imus is the official capital.

PSGC: 043400000
ISO: LAG
Province Capital: Santa Cruz
Area Code: 49
Congressional Districts: 4
Cities: 3
Municipalities: 27
Barangays: 674

1571: Laguna province created.
March 10, 1917: Province established by Act No. 2711.

PSGC: 045600000
ISO: QUE
Province Capital: Lucena City
Area Code: 42
Congressional Districts: 4
Cities: 2
Municipalities: 39
Barangays: 1,242

1591: Kalilaya province created from Batangas and Laguna.
Middle 18th Century: Kalilaya renamed Tayabas.
June 12, 1902: La Infanta district and El Principe district annexed.
November 10, 1902: Marinduque annexed by Act No. 499.
March 10, 1917: Province established by Act No. 2711.
September 7, 1946: Tayabas renamed Quezon by Republic Act No. 14.
September 7, 2007: Quezon del Norte province and Quezon del Sur province created from Quezon by Republic Act No. 9495, but defeated by plebiscite.

¹ Part of Quezon del Sur.
² Quezon del Sur province capital.

PSGC: 045800000
ISO: RIZ
Province Capital: Pasig, City of *
Area Code: 2
Congressional Districts: 4
Cities: 1
Municipalities: 13
Barangays: 188

1853: Morong district created from Laguna.
June 11, 1901: Rizal province created from Manila and the Morong district by Act No. 310.
March 10, 1917: Province established by Act No. 2711.

* Currently, Pasig, City of, is the capital of the Rizal province although it is actually outside of the province. There may be plans to establish a new capital within the Rizal province with Antipolo, City of, being the most likely choice. Some sources suggest that Antipolo, City of, has already become the new province capital.