The "Four Branches of the Mabinogi" is a collection of Welsh mythological tales that are part of the Mabinogion, a medieval manuscript. Each branch tells a distinct story featuring legendary figures, including Pwyll, Bran the Blessed, and Rhiannon. These tales explore themes of love, betrayal, and the supernatural, reflecting the rich cultural heritage of Wales. The four branches are titled Pwyll Prince of Dyfed, Branwen Daughter of Llŷr, Manawydan Son of Llŷr, and Math Son of Mathonwy. Together, they weave a complex narrative that highlights the interconnectedness of characters and events, showcasing the importance of honor and destiny in Celtic mythology.