Indrajit was named as Meghnaada at his birth because when the child cried for the first time, thunder and lightening resounded, signifying the birth of a great warrior. Lord Brahma conferred his cognomen Indrajit upon him when he defeated and imprisoned Indra, the king of gods. Indrajit was neither a deva (god), nor a bhakta (devotee) but still he was so renowned because of his courage and efficiency in battle. Though Indrajit was a rakshasa, still his respect for his father Ravana paralleled Rama's devotion to his father Dasaratha. Indrajit realized that Lakshman was the incarnation of a divine being and it was not easy to defeat him, still he chose to fight him till the end according to his father's wish rather than selecting a disgrace of leaving the battle.
Indrajit was married to Sulochana (also known as Prameela). Prameela came from the nagas and was daughter of Adishesha, who was the incarnation of Lakshmana according to some sects.
When Indrajit got his victory over Indra, he was granted with a Brahmastra. It is believed that Brahmastra was a great weapon having tremendous power and when it left the bow it could beat any arrow and kill any person at wish.
Indrajit took a significant role in the Great War between Rama and Ravana. He had access to all the divine weapons like Brahmastra, Pashupatastra etc. Indrajit even bound Rama and Lakshman under the 'Nagpash' (serpent spell). The king of birds Garuda subsequently freed Rama and Lakshman from the Nagpash by killing the serpents.
Indrajit was unbeatable in any war as he carried out Yajna(sacrifice) before any battle, and could only be killed by enemy force who destroyed the Yajna. Lakshman attacked the Yajna with the help of Sugreeva and successfully destroyed it. Indrajit came out of the temple and had a terrible battle with Lakshman. He shot Brahmastrato kill Lakshman but the missile denied to kill him. He shot Pashupatastra, which Shiva bestowed him but it also denied to kill his enemy.
Finally Indrajit used the most powerful missile of the three worlds to slay Lakshman but it was also unsuccessful. After that Indrajit knew that it would be difficult to defeat Lakshman and used his magical power to transport himself to his father Ravana's palace. He tried to pursue Ravana once again to bow before Rama and adapt the side of truth but Ravana was stubborn at his resolve and Indrajit's efforts were all in vain. Indrajit then said goodbye to his mother Mandodari and his wife Sulochana for the last time.
Finally Indrajit returned to the battlefield. Frightful war started between Indrajit and Lakshman and Lakshman pierced Indrajit's neck with his arrows, which caused his death. The army of Rama was overjoyed with the success and wanted to celebrate the victory by desecrating Indrajit's body. But Rama was a virtuous man and adhered to his 'Dharma'. Rama said that Indrajit was his enemy when he was alive but now that He is dead he is no more their enemy. Rama took off his shawl and covered the body of the slain warrior and asked Hanuman to carry the body to the main entrance of Lanka so that royal family could carry out the funeral process of Indrajit.