Advent of Krishna

Kamsa's reign of terror continued. He forcibly occupied the kingdoms of the Yadu, Bhoja, and Andhaka dynasties and the kingdom of Surasena. He forged alliances with many Satanic kings and princes. Among his allies were demons like Pralamba, Baka, Canura, and Trinavarta.  His friends included the machiavellian demons Aghasura, Mustika,  Arista, and Dvivida. The host of evil kings and princes also included the she-demon Putana, and monsters like Kesi and Dhenuka.

Kamsa and allies

Kamsa allied himself with despots and tyrants like King Jarasandha, lord of Magadha, Banasura and Bhaumasura, and other murderous rulers until he was the most powerful of all.
At this time, he took measures against the families of the Yadu dynasty into which Krishna was to take His birth. He laid plots and called his wicked counselors, Kesi and Putana, and began a campaign of repression against the Yadus, the Bhojas, and the Andhakas.

Devas

His father-in-law Jarasandha provided troops and warriors, elephants and horses to march into the city of Mathura and search from house to house those suspected of being aligned with the devas.

Mathura

A panic ensued among the general populace of Mathura. Innocents were arrested and murdered. Blood ran in the streets. Many people fled or went into hiding. Vasudeva sent his first wife, Rohini to Vrindavan. There she could find shelter with Nanda Maharaja, a friend of the family. Nanda Maharaja was the leader of the men who kept dairy cows for milking in the town of Gokula.  Rohini was sent to live with Nanda Maharaja and his wife, Yashoda, there in Vrindavana by the banks of the Yamuna where the peacocks played in the morning sun.

Vrindavana

During King  Kamsa's demonic reigh of terror, the leaders of the Yadu, Bhoja and Andhaka dynasties took refuge in the lands ruled by the Kurus, in the nations of the Pancalas and the city-states of  Kekaya, Salva, Vidarbha, Nisadha, Videha and Kosala.

Ancient Cities of India

And so, determined to attain hegemony over all of India Kamsa destroyed the union of the Yadu dynasty and broke the influence of the Bhoja and Andhaka families. In this way he consolidated his power within the land known as  Bharata.

Cruel King Kamsa

When Kamsa slaughtered the children of Devaki and Vasudeva his friends and relatives tried to stop him. But to no avail. They were arrested and put to death or converted to his cause.

Vasudeva and Devaki spent a long time languishing in the dungeons of this terrible despot. But their destiny was foretold by the thunderous voice that had interrupted the wedding party so long ago.
Soon  Devaki became pregnant for the seventh time.  And with this a special avatar called Ananta appeared within her womb. She was overjoyed, but fearful.  She was joyful that  she was carrying divinity within her, but concerned about the wrath of Kamsa. With this, Bhagavan Sri Krishna arranged a mystical transfer with the power of Yogamaya: the child of Devaki was transferred  from the womb of Devaki to the womb of Rohini, the wife of Vasudeva who had taken shelter with Nanda Maharaja in Vrindavana.

Yogamaya transferring the 7th Child of Devaki, Balarama from the prison of Kamsa, to Rohini in Vrindavana

He would be born as Balaram, and Yogamaya would take birth as the daughter of Yashoda, Subhadra.
 On account of being forcibly attracted to the womb of Rohini, the son of Rohini would be known as Sankarsana and would be the source of all spiritual power or bala, by which one could be able to attain the highest bliss of life which is called ramana. Therefore the plenary portion Ananta would be known after His appearance either as Sankarsana or Balarama.

Krishna and Balarama

When the Supreme Powerful Personality of Godhead transferred Lord Sesa from the womb of Devaki to the womb of Rohini, both of those ladies were under the spell of Yogamaya.

When this was done, people understood that Devaki's seventh pregnancy was a miscarriage. Thus although Balarama appeared as the son of Devaki, He was transferred to the womb of Rohini to appear as her son.

Rohini and Balarama

News reached Kamsa that Devaki's pregnancy had ended in a miscarriage. That cruel and terrible despot went to the depths of his dungeon to confirm the death of Devaki's seventh child.
Passing through the dark corridors of stone, past the miserable prisoners who inhabited the walled cells, Kamsa passed his father Ugrasena, who was in chains, until he reached the cell of Vasudeva and Devaki. Ordering the guards to open the massive iron door, he entered.

"Vasudeva, my brother-in-law. And Devaki, my dear sister. Some awful news has come to me.  I have heard that you are not feeling very well.  I have ordered a full breakfast for both of you with some fresh fruit. Is it true that you have had another child?"
"Alas," said Devaki. "That child is no longer with us."
"And where is the little creature," said Kamsa.
"I'm not sure. I don't remember." said Devaki.
"I am afraid she lost the child," said Vasudeva.
"Lost the child? How is it possible? Guards!"

Vasudeva and Devaki in the prison of Kamsa, artist's depiction.

Kamsa called the guards and asked them about the missing infant, but there was nothing they could say. They had seen nothing. Kamsa was suspicious, but there was nothing he could do.  Convinced that the seventh child had somehow taken birth, he decided to take measures against the conception of the eighth child. He had the guards bring heavy chains and had Devaki bound to one pillar and Vasudeva bound to another. "Let them conceive a child bound thus," he thought, as he left them to their fate and strode through the dungeons to the royal palace.

 Bound in chains and misery, Vasudeva prayed to Vishnu, Lord of the universe. He felt a ray of illumination. And while he sustained the divine form of the Supreme Personality of Godhead within his pure heart, Vasudeva appeared just like the sun whose shining rays are scorching to the common man. And now that  Krsn had entered his heart and mind as the Lord of the whole creation.  Vasudeva communicated this miracle to his wife Devaki by mental transmission and in this way,  Lord Krsna situated Himself transcendentally  in the unalloyed heart of Devaki.

Krishna was transferred from the heart and mind of Vasudeva to womb of Devaki by divine conception

And so by miraculous, divine conception, Krishna was transferred into the womb of Devaki by Vasudeva's brilliant mind exactly as the setting sun's rays are transferred to the full moon rising in the east. And so it was that Krishna entered the body of Devaki from the mind of Vasudeva through transcendental means. In this way, Devaki became the residence of  Godhead who is one without a second and the cause of all creation.

Godhead

In time, Kamsa, visited the prison again. He saw the transcendental beauty of his sister Devaki, and concluded that the Supreme Personality of Godhead had taken shelter in her womb.
He could understand that there was something wonderful within the womb of Devaki.and so became perturbed.

"It's time to kill Devaki!"

It was time to kill Devaki, so that Krishna would never take birth in this world and fulfill the prophecy of the thunderous voice from the clouds.