The Central Bank of Philippines was established on January 3, 1949 as the country's central monetary authority. Forty-four years later, the Bangko Sentral ng Pilipinas (BSP) took over as the central bank of the Republic of the Philippines in accordance with the provisions of the 1987 Philippine Constitution and the New Central Bank Act of 1993.
The BSP oversees the circulation of the New Generation Banknote Series of the Philippine peso. Here are some observations about the six denominations, namely 20 pesos, 50 pesos, 100 pesos, 200 pesos, 500 pesos and 1,000 pesos:
* Of the nine persons whose portraits appear on these denominations, only three were born during the twentieth century: Diosdado Macapagal (1910), Benigno Aquino Jr. (1932) and Corazon Aquino (1933). Interestingly all of them were born in Region III or Central Luzon.
* The other six were born during the nineteenth century: Sergio Osmena (1878), Manuel L. Quezon (1879), Jose Abad Santos (1886), Vicente Lim (1888), Manuel A. Roxas (1892) and Josefa Llanes-Escoda (1898).
* There are two persons named "Manuel" on Philippine banknotes. Manuel L. Quezon on the 20-peso bill and Manuel A. Roxas on the 100-peso bill. Moreover, both Quezon and Roxas died in 1944 and 1948, respectively, while serving as President of the Republic.
* Four persons who never became president appear in the banknotes. They are Benigno S. Aquino Jr. on the 500-peso bill. On the other hand, portraits of Vicente Lim, Jose Abad Santos and Josefa Llanes Escoda appear on the 1,000-peso bill.
* There are two persons prominently shown on the obverse side of in the 500-peso bill, while there are three persons in the 1,000-peso bill. There are two zeros in the number "500," whereas there are three zeroes in the number 1,000. Could the number of zeroes represent the number of heads?
* Six animals are represented on the reverse sides of these denominations. The only invertebrate is the pearl oyster (Pinctada maxima) on the 1,000-peso bill. The rest are vertebrates.
*The palm civet (Paradoxurus hermaphroditus philippinensis) on the 20-peso bill and the tarsier (Tarsius syrichta) on the 200-peso bill are land mammals. The scientific name of that tarsier, however, should have been Carlito syrichta.
* Along with the pearl oyster, the maliputo fish (Caranx ignobilis) on the 50-peso bill and the whale shark (Rhincodon typus) on the 100-peso bill live in water.
* A stylized Philippine eagle, the national bird, is included in the BSP logo on these banknotes. The blue-naped parrot (Tanygnathus lucionensis) is also present on the 500-peso bill.
*Similar with Mayon Volcano on the 100-peso bill, Taal Lake on the 50-peso bill is volcanic in nature.
* UNESCO World Heritage Sites can be seen on the lowest- and highest-valued banknotes: Banaue Rice Terraces on the 20-peso bill and Tubbataha Reefs Natural Park on the 1,000-peso bill.