Calabarzon

Calabarzon (officially stylized in all caps; English: /kɑːlɑːbɑːrˈzɒn/; Tagalog: [kalɐbaɾˈsɔn]), sometimes referred to as Southern Tagalog (Tagalog: Timog Katagalugan) and designated as Region IV‑A, is an administrative region in the Philippines. The region comprises five provinces: Batangas, Cavite, Laguna, Quezon, and Rizal; and one highly urbanized city, Lucena. It is the most populous region in the Philippines according to the Philippine Statistics Authority (PSA), having over 16.1 million inhabitants in 2020, and is also the country's second most densely populated after the National Capital Region. It is situated southeast of Metro Manila, and is bordered by Manila Bay and South China Sea to the west, Lamon Bay and the Bicol Region to the east, Tayabas Bay and the Sibuyan Sea to the south, and Central Luzon to the north. It is home to places like Mount Makiling near Los Baños, Laguna, and Taal Volcano in Batangas.

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. 103.

The history of the area now known as Calabarzon dates back to early historic times. Local historians believe that three of the 10th 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 de Bay; 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. Since the Spanish colonial period of the Philippines, the region has served as home to some of the most important Philippine historical figures, including the Philippine national hero, José Rizal, who was born in Calamba.