The region itself is relatively flat, but also consists of coastal areas and highlands. The region is the 12th largest region in the Philippines, with an area of 16,873.31 km 2. See also: Cavite § Geography, Laguna § Geography, Batangas § Geography, Rizal § Geography, and Quezon § Geography 10879 renamed "Region IV-B" into the "MIMAROPA Region". 246, which declared Calamba as the regional center of the region. The next year, Arroyo signed Executive Order No. Aurora was transferred to Region III, Central Luzon. Due to its size, Region IV was split into two separate regions, Region IV-A (Calabarzon) and Region IV-B (Mimaropa). 103, which reorganized the Southern Tagalog region. On May 17, 2002, President Gloria Macapagal Arroyo signed Executive Order No. In 1979, Aurora formally became a province independent of Quezon and was also included in Region IV. At this time, Region IV consisted of Batangas, Cavite, Laguna, Marinduque, Oriental Mindoro, Occidental Mindoro, Quezon, Rizal, Romblon, and Palawan. The IRP created Region IV, known as the Southern Tagalog region, and was the largest region in the Philippines. 1, which organized the provinces into 11 regions as part of Marcos' Integrated Reorganization Plan. On September 24, 1972, President Ferdinand Marcos enacted Presidential Decree No. In 1951, the northern part of Quezon became the sub-province Aurora, named after Quezon's wife. Quezon was the second President of the Philippines and a native of Baler (now part of Aurora). 14, which renamed the province of Tayabas to Quezon, in honor of Manuel Quezon. On September 7, 1946, the Third Philippine Republic enacted Republic Act No. Ultimately, Sakay's Tagalog Republic ended in 1906 when he and his men were betrayed under the guise of holding a national assembly aimed at the self-determination of the Filipino people.
In 1902, Macario Sakay, a veteran Katipunan member, established the Tagalog Republic in the mountains of Rizal.
The new province comprised 29 municipalities, 17 from Manila and 12 from Morong. 137 of the First Philippine Commission abolished Morong and created a new province, named after the Philippines' national hero, Jose Rizal, who, coincidentally, was a native of Laguna. On June 5, 1901, a convention was called on whether or not the province of Manila should annex the province of Morong, which was found to be unable to be self-sufficient as a province. The name of the region is an acronym of its five component provinces: Cavite, Laguna, Batangas, Rizal and Que zon.
Since the Philippines' colonial period, the region has served as home to some of the most important Philippine historical figures, including the Philippines' national hero, José Rizal, who was born in Calamba. Local historians believe that three of the tenth century place-names mentioned in the Philippines' earliest known written document, the Laguna Copperplate Inscription, pertain to regions or polities (Tagalog: " bayan") along the shores of Laguna Lake and some Filipino-Chinese scholars believe the tenth century trading polity known as Ma-i may actually have been the predecessor of the present day town of Bay, Laguna. The history of the area known as Calabarzon dates back to early historic times. Prior to its creation as a region, Calabarzon, together with the Mimaropa region, the province of Aurora and several parts of Metro Manila, formed the historical region known as Southern Tagalog, until they were separated in 2002 by virtue of Executive Order No. It is home to places like Mount Makiling near Los Baños, Laguna and the Taal Volcano in Batangas. The region is situated southeast of Metro Manila, and is bordered by the Manila Bay to the west, Lamon Bay and the Bicol Region to the east, the Tayabas Bay and Sibuyan Sea to the south, and Central Luzon to the north. The region is the most populous region in the Philippines according to the Philippine Statistics Authority, having over 14.4 million inhabitants in 2020, and is also the country's second most densely populated after the National Capital Region. The region comprises five provinces: Batangas, Cavite, Laguna, Quezon, and Rizal and one highly urbanized city, Lucena. Calabarzon ( /ká-lɑ-bɑr-zon/), formally known as the Southern Tagalog Mainland, is an administrative region in the Philippines, designated as Region IV-A.