Hanuman was just one of such 4 monkeys. This monkey team was instrumental in supplying Rama crucial information regarding Sita. They aided him make a bridge over the seas, and cross around by using a monkey army that properly stormed the demon stronghold and freed Sita. भस्मसादभवदैत्यो दुष्टचेष्टितमन्तकृत् ॥ २३ https://tantramantraaurvigyaan.com/