Porridge

When Dasarat, the ruler of Ayodhya performed the Yagna sacrifice seeking issues to succeed him on the throne, a pot of porridge emerged from the fires. This was shred in three cups among the three queens of Dasarat. The third one namely Sumitra had placed it on the terrace wall, which was lifted and carried away by an eagle.

To compensate the loss, the two other queens Kausalya and Kaikeyi shared the porridge from their cups with Sumitra. Kausalya gave birth to Rama, Kaikeyi mothered Bharat and Sumitra bore two children Lakshman and Shatrugna.

At the behest of Lord Shiva, the third portion of the porridge that was carried away by the eagle was directed by the force of wind god (Vayu) to the place where Anjana was deeply engaged in the worship of Shiva.

Anjana got to eat the porridge and then gave birth to Hanuman. Thus, we can say that in a way Hanuman was one of the brothers of Rama. This is the reason why Hanuman was so powerful and mighty on par with the other four brothers.

https://www.speakingtree.in/blog/how-did-hanuman-get-his-name