Proclamation of Rama as King

Vishwamitra was given a warm and cordial farewell by King Janaka. Bharata and Shatrughna went with their Uncle to stay with the maternal grandfather of Bharata at the kingdom of Kaikey. The days passed by in peace and joy. King Dashratha held a counsel with his ministers regarding the appointment of Rama as Yuvaraj and choosing him as the heir to the throne. His decision was approved by his court and hailed by senior citizens and prominent people of Ayodhya.
People burst into celebration to herald the choice of Rama as Yuvaraj (young King) and Ayodhya resounded with the music while Mangalkalash (auspicious pots) were placed at crossroad, and gates of the city. When Kaikeyi’s favorite maid Manthara saw this spectacle, she became very envious.
She burnt with anger and resentment when she saw people making merry, singing and dancing as they rejoiced at the choice of Rama. She went to Kaikeyi’s palace and filled her ears with devious gossip and malicious thoughts. She told her that if Rama becomes the king then Kaushalya will become the most important queen and would treat Kaikeyi as a slave. When Manthara saw that the queen was being swayed by her, she used another ploy. She told Kaikeyi that she could still turn the game around to her advantage if she used the two boons given to her long ago by Dashratha. Instigated by Manthara’s evil plans, Kaikeyi went into the kopbhuvan or sulking room. Kaikeyi threw off her jewels, wore a drab black garment, made her hair disheveled and flopped on the bed in an angry pose.
Proclamation of Rama as King, Ramayana – The Epic Story