Soon after the Ashwamedha Yagna and eating of the divine dessert by the queens, they gave birth to beautiful sons. Rama was born to Kaushalya, Lakshmana and Shatrughna to Sumitra and Bharata to Kaikeyi. They were brought up with all the riches and the best of the scholars and warriors had come to Ayodhya to teach them various skills ranging from warfare, weapon skills, to survival and life skills. The four brothers became learned not only in terms of war and martial arts but also in aspects like divine knowledge of Vedas and education about the world.
Dasharatha was very happy seeing his sons becoming extremely skilled in various aspects of life and he was now satisfied that Ayodhya would never be without a noble king. All the queens loved each of the children equally and were delighted with their deeds and values. They were blessed and could not thank God enough for this divine gift.
One day, sage Vishvamitra had come to Ayodhya for a special task. He experienced a royal stay in the palace and had a good feast. After that, Dashratha asked Vishvamitra if he could be of any service to the sage. Vishvamitra replied that he wants Rama to come and help him in conducting the Yagna. Whenever he sat to perform the Yagna, demons of Ravana named Subahu and Mareech hindered their rites and would cause trouble to all the priests there. Vishvamitra was a learned priest and he could also kill the demons but he had taken an oath that he would never lift any weapon in anger. Hence, Vishvamitra asked Dasharatha if he could send his eldest son Rama to defeat the mighty demons and help him in performing the Yagna.
Dasharatha was shocked to hear this request. He could not consider the idea of his sons going far from him and that too in a dangerous situation where they would have to fight a demon. He refused to send his children to this danger and offered to go himself and fight off these demons. Vishvamitra said that they would only be killed by Rama and no other would be able to kill them. No army or king except Rama had the power to do so. Vishvamitra felt that Dasharatha will not live up to his promise to serve him and was upset. Sage Vashishtha then consulted Dasharatha and he finally agreed to send his sons to the forest with Vishvamitra.
Thus, Rama prepared to go to the forest and defeat the demons. However, Lakshmana was also adamant to accompany his elder brother and Dasharatha also saw this. Dasharatha immediately agreed and thought that Lakshmana would not only help his brother but they both would also protect and care about each other so there would be a little cause for worry. Dasharatha also ensured that they consult Vashishtha once before they leave and learn anything that would be useful in their journey. Vishvamitra was pleased to hear this and he ensured that they would be safe and he would also teach them whatever he knows.