According to the Book of Genesis, Naphtali (/ˈnæftəlaɪ/; Hebrew: נַפְתָּלִי, Modern: Naftalī, Tiberian: Nap̄tālī, "my struggle") was the sixth son of Jacob, the second of his two sons with Bilhah. He was the founder of the Israelite tribe of Naphtali.
Some biblical commentators have suggested that the name Naphtali may refer to the struggle between Rachel and Leah for the favours of Jacob. Bilhah was the handmaid of Rachel, who was infertile at the time, and had persuaded Jacob to have a child with Bilhah as a proxy for having one with herself.
–Wikipedia