The Republika ng Katagalugan (Tagalog Republic) was the short lived republic in the mountains of southern Luzon founded in 1902 by members of the Filipino Katipunan. The term "Katagalugan" may also refer to the tagalophone, or Tagalog-speaking regions.
Republika ng Katagalugan is the name of the original council under Andres Bonifacio founded in 1892. General Macario Sakay held the presidency with Francisco Carreón as vice president. In April 1904, Sakay issued a manifesto declaring Filipino right to self-determination at a time when support for independence was considered a crime by the American occupation forces in the Philippines.
The republic ended in 1907 when Sakay and his leading followers were arrested and executed by the American authorities as bandits. Some of its survivors escaped to Japan to be joined with Artemio Ricarte, and later returned to support the Japanese-sponsored Second Philippine Republic during World War II.