Southern Tagalog, or Region IV, (Tagalog: Timog Katagalugan) was a region of the Philippines that comprised what are now Region IV-A (CALABARZON) and Region IV-B (MIMAROPA). Region IV was partitioned into the two regions on May 17, 2002.

History

Prior history and partition

Southern Tagalog was the largest region in terms of both area and population. It comprised the provinces of Aurora (now part of Central Luzon), Batangas, Cavite, Laguna, Marinduque, Oriental Mindoro, Occidental Mindoro, Quezon, Rizal, Romblon, and Palawan. Quezon City was the designated regional centre of Southern Tagalog. The former region covered the area where many Tagalog speakers reside; the two other majority-Tagalophone regions are the National Capital Region and Central Luzon.
By virtue Executive Order No. 103, dated May 17, 2002, Region IV was divided into Region IV-A (CALABARZON) and Region IV-B (MIMAROPA).

Transfer of Palawan

Palawan was transferred to Region VI (Western Visayas) on May 23, 2005 by virtue of Executive Order 429. However, Palaweños criticised the move citing a lack of public consultation. Most residents of Puerto Princesa and all but one of the province's munipalities preferred to stay in Region IV-B.^[1]

Consequently, Administrative Order No. 129 was issued on August 19, 2005 to address this backlash directing the abeyance of Executive Order 429, pending the approval of an implementation plan for the orderly transfer of Palawan from MIMAROPA to Region VI. Presently, Palawan is still considered part of MIMAROPA.^[2]