The Philippines is used in English because historically, the country was named after King Philip II of Spain when it was a Spanish colony. The use of the before the country name is a translation of the Spanish naming convention las Islas Filipinas which means the Philippine Islands. Over time, this linguistic convention was carried over into English. This usage of the distinguishes the Philippines as a group of islands, rather than just a singular landmass. Thus, it has become standard to include the before Philippines in English.
