Lakshmana, also spelled as Laxmana, was the younger brother of Prince Rama and his loyalist in the Hindu epic Ramayana. He was the twin of Shatrughna.
In the Puranas, Lakshmana is described as an incarnation of Shesha, the multiple-headed naga (serpent) upon whom rests the preserver deity Vishnu, whose avatar Rama is considered to be. Lakshmana was especially attached to Rama. When Rama married Sita, Lakshmana married Sita's younger sister, Urmila. They had two sons: Angada and Chandraketu.
Later, when Rama was exiled for fourteen years on the insistence of Kaikeyi, Lakshmana left his wife Urmila and joined Rama and Sita in exile. (source-wikipedia)