How did Kusha become the King of Ayodhya, and what was his rule like after Rama left for Vaikuntha?

Maharaja Kusha

Kusha was the eldest son of Shri Ram and Mata Sita. In original Valmiki Ramayana it's simply written Shri Ram gave North Kosala to Lava and South Kosala to Kusha to rule as it's Kings. Their married life or their life after Vaikuntha Gaman of Shri Ram is not mentioned.

However, as Kusha was the one who inherited the throne of Ayodhya, he is mentioned in detail in Ananda Ramayana, Raghuvansh and his genealogy is mostly present in Puranas and Shrimad Bhagwatam.

In Raghuvansh written by Kalidas, it's mentioned that when he was ruling in Kushavati, he was visited by deity of Ayodhya who pleaded him to return back as the glorious city got dilapidated after Shri Ram.

Now that powerful King Kusha, who was the banner of his family, who had implanted arrowheads in the hearts of his enemies, and who was a friend to his subjects, encamped on the outskirts of the city those armies which had waving banners. [16-37]

King Kusha, the son of Maithili, living in the residential city of Raghu-s which had been restored to its former splendour, did not covet for the city of the lord of heavens, namely amarAvati of Indra, or even for the city of god of wealth, namely alakA-puri of Kubera. [16-42]

Kusha eventually returned after discussing with his ministers and rebuilt the city to its former glory and became the most illustrious king in Aryavarta. He is called King of Kings and even Devtas in Ananda Ramayana.

• Lines shaped like the Srivatsa mark, thunderbolt (Vajra), discus (Chakra), lotus, fish, bow, and mace (Danda) are marked on his hands, indicating that he will be a king even among the gods. || 41 ||
• He has a complete set of thirty-two teeth in his mouth. His neck is beautiful like a conch shell. His voice is deep and resonant like that of a Krauncha bird, a kettle-drum (Nagada), a swan, and a thundercloud. From this, it is known that he will surpass all the kings of the world. || 42 ||

Mahadevi Champika

Champika, daughter of Maharaja Bhurikirti was his first wife and she chose Kusha in Swayamvar.

• Hearing these words of Nanda, Champika, with a smiling face, happily placed the bridal garland around Kusha's neck with her own hands.
• At that moment, various divine drums resounded, and the bards and panegyrists sang praises. Sitting in that assembly with his head bowed down out of shyness, the young Kusha looked exceedingly handsome.

Rishi Agastya told Shri Ram that Champika won't be having any sons but daughters only and therefore when he had left for Vaikuntha, Kusha would get a second wife named Kumudvati and she will give him sons. After that they had nine daughters together.

Kumudvati

After he became King of Ayodhya, Kusha got married to Naga Princess Kumudvati, sister of Naga King Kumud in a peace alliance when he had almost annihilated Nagas due to Kumudvati taking his lost golden arm- bracelet mistakenly when he was sporting in Sarayu river with Champika (and his junior wives in Raghuvansh).

The king did not bear loss of bracelet because it was the charm securing victory; further it was worn by his father Rama before him, but not because he was avaricious for gold pieces; for a firm-minded person, as the king was, equally valued perishable flowers and variable ornaments. [16-74]

Kumuda who spoke in this manner, and who returned the ornament to the king who in turn replied "you are praiseworthy and a relation of mine from now on..."; then accompanied by his kinsmen Kumuda formed an alliance with the king by procedurally giving over the jewel of his dynasty which was no other than his sister Kumudvati.

In this manner the Naga king Kumuda got the direct son of Seetha and Rama, the legitimate descendant of the ruler of the three-worlds, as his kinsman whereby Kumuda gave up the fear from the bird-vehicle of Vishnu, namely Garuda, who had been his enemy in consequence of the death of Kumuda's father; and Kusha too got Kumuda who was the fifth descendant of Takshaka, a legendary serpent king, as his kinsman whereby the vexatious problem with serpents is obliterated on earth and the king Kusha ruled the country to the utmost delight of his subjects. [16-88]

Kusha and Kumudvati (in Ananda Ramayana) had eight sons and a daughter named Champakmalini. In Raghuvansh their eldest son Atithi is mentioned who inherited the throne after Kusha died and Kumudvati followed him in death as she couldn't live without her husband.

Sources: Raghuvansh by Kalidas and Ananda Ramayana

What is the story of Kusha's daughter Hema, and how does her marriage reflect the customs of that time?

 

Kusha , Champika and their daughter Hema

Kusha, the eldest son of Shri Ram and Mata Sita was married to Princess Champika, daughter of Maharaja Bhurikirti. Rishi Agastya after their marriage prophesized to Shri Ram that Champika won't be having any sons but daughters and when Shri Ram had left for Vaikuntha, Kusha would get a second wife named Kumudvati and get sons.

Kusha and Champika started their marital life and they had nine daughters together. Once Shri Ram organised a grand Swayamvara for Hema, beautiful and illustrious daughter of Kusha and Champika. Many Kings were invited in the Swayamvara along with Prince Chitrangad of Avanti.

Chitrangada fell in love with beautiful and illustratious Hema and wished to marry her. He hypnotized everyone in the Swayamvara while Shri Ram and other elders were away and took Hema on his chariot and left but he didn't go to Avanti and stopped midway as he considered it wrong to take her away like this. But it was too late, the royal house found it insulting and Lava and others attacked him in which Lava got unconsious. Then Kusha came and defeated Chitrangad and his father Ugrabahu and took them to Shri Ram. Shri Ram forgave them due to friendly relationship with Avanti and the good behaviour of the father and son in the past. It's not properly written but it's hinted that Hema was married off to Chitrangad as usually happened in such situations.

Shri Ram gave Kusha his famous golden arm- bracelet after this victory which was originally gifted to him by Rishi Agastya and years later this very bracelet became the reason of the union of Kusha and his love Kumudvati and the birth of meritorious, handsome and intelligent Atithi, the scion of Raghu and worthy grandson of Shri Ram.

Ananda Ramayana is considered a late source although it's writer is called Maharishi Valmiki. The source mentions history of sons of Lord Ram and his siblings.

Source- Ananda Ramayana

What happened to Raghu Vansh after Lava and Kusha?

Mahadevi Kumudvati

Devi Champika

Kusha , son of Lord Ram and Goddess Sita had married Champika, Princess of Eastern Lands and daughter of Maharaj Bhurikirti. Champika had chosen him in a Swayamvar. Kusha and Champika had nine daughters.

Maharaja Atithi

When Shri Ram left for Vaikuntha, deity of Ayodhya requested Kusha to come to Ayodhya and rebuild it. Kusha eventually came and rebuilt the city to its former glory. Once when he was on a pleasure tour in Sarayu river, he lost a golden bracelet gifted by his dear father. Soon, Naga King Kumud along with his beautiful sister Kumudvati came out of the river and requested Kusha to accept the bracelet along with his sister. Kusha gladly accepted her hand in marriage and they got married immediately and gods blessed the union. They soon got a son whom they named Atithi.

When Kusha died fighting a demon named Durjaya who fatally injured him, Kumudvati immediately lost her life like how moonshine follows the moon.

The ministers appointed atithi as the new king as Kusha had wished. Atithi is said to be an extremely intelligent, handsome and passionate King and he instead of killing his rival kings, put them on the Thrones as vassals thus being a highly strategic and diplomatic King.

The love stories of Aja and Indumati , Shri Ram and Mata Sita and Kusha and Kumudvati are heart warming in Raghuvansh. In Ananda Ramayana, Kumudvati and Kusha had 8 sons and 1 daughter and Atithi was their eldest son.

Source- Raghuvansh by Kalidas

Who was Atithi, the son of Kusha and Kumudvati, and what role did he play in Ayodhya's lineage?

Atithi was son of Kusha and his Chief Queen Kumudvati. He succeeded at the throne of Ayodhya after death of his father Kusha. He had married a Princess of Nishadha Kingdom (somewhere in Himalayan plateau) and also named his son and successor Nishada in her honour.

Kumudvati

Kumudvati was second wife of Kusha but his Chief Queen. She was a Naga Princess and sister of Naga King Kumud. She had eight sons and the eldest son was Atithi. She also had one daughter with Kusha named Champakmalini.

Kusha’s first wife was Champika, daughter of King Bhurikirti of Eastern lands. She gave birth to nine daughters and one of them was named Hema, who became Queen of Avanti.

Atithi was handsome, patient, wise, charitable and a good administrator. He was known for his charity and making the kings he defeated as his vassals.

Source- Ananda Ramayana and Raghuvansh by Kalidas