Goodluck Caubergs died the day after nurse Grace Adeleye carried out the procedure without anaesthetic and using only a pair of scissors, forceps and olive oil, Manchester Crown Court heard.
The 66-year-old medic is originally from Nigeria, as are the youngster’s parents, where the circumcision of newborns is the tradition for Christian families, the jury heard.
Adeleye, also a midwife, was paid £100 to do the operation as Goodluck’s parents were not aware the procedure was available on the NHS.
The Royal Oldham Hospital was just a mile and a half from the family home in Chadderton, near Oldham, but by the time an ambulance was called the child could not be saved.
Adeleye, of Sarnia Court, Salford, Greater Manchester, denies manslaughter by gross negligence of the baby boy.
It is alleged she botched the procedure by leaving a 'ragged' wound that bled, and her post-op care was also woefully inadequate.
Adrian Darbishire QC, opening the case for the prosecution, told the jury: 'The allegation essentially here is that the care she provided in the course of that procedure was so bad that not only did it cause the death of that young baby wholly unnecessarily, but it amounted to gross negligence and a crime.'
Mr Darbishire said circumcisions were routinely carried out among Christian families in Nigeria who brought the tradition with them to the UK, and the procedure was an 'ancient, well established and widespread' practice across the world.
But the court heard that up to three children a month are admitted to the Royal Manchester Children’s Hospital due to bleeding after home-based circumcisions - a danger the nurse should have been aware of.
Goodluck was born on March 22, 2010, in Rochdale and died on April 17, the day after the circumcision, aged 27 days.
Adeleye then brought her 'instruments' out of her handbag and dipped a pair of scissors into the water in a kidney dish.
'At that point Sylvia closed her eyes,' Mr Darbishire said.
'Goodluck had had no anaesthetic or local pain relief at this point and that is not how this should be done.
'By the time Sylvia opened her eyes the operation was over.
'She could see the foreskin between the blades of the scissors.'
Adeleye was introduced to Goodluck's family through a friend as she had performed many circumcisions
Adeleye then cleaned the wound with cotton wool and applied a bandage.
The boy was 'crying throughout' and the wound was bleeding, but Adeleye told the mother this was normal, the court heard.
The defendant left the house between 30 and 40 minutes after surgery and the £100 had been handed over, without any proper checks on the patient after the procedure, it is alleged.
Later the parents found the bandage had come off the wound, which dripped with blood and there was blood in the child's nappy.
Mr Darbishire said even a small amount of blood loss is dangerous and the loss of just one sixth of a pint of blood can be fatal for a newborn.
The concerned parents, who had no medical training, called the defendant around two and a half hours later.
Adeleye told them the bleeding was normal and 'not a problem' and advised a change of nappy and bandage and to apply olive oil.
In fact Adeleye should have advised immediate medical attention.
'To delay and reassure was simply not appropriate,' the prosecutor told the jury.
'His parents remained concerned but they had been reassured by the defendant.'
However, the following morning it was clear something was wrong and at 7.20am an ambulance was called.
Mr Darbishire added: 'I have no doubt there will be much criticism of the parents by their inaction.
'But can I invite you to consider this. One of the hardest things as a parent, especially parents of a young child, is knowing when to be worried and how worried to be.
'But on the other hand no one wants to make a fuss about nothing.'
A post-mortem examination found Goodluck died from blood loss after the op.
Mr Darbishire said: 'His death was wholly unnecessary. He bled to death over a period of many hours when medical assistance, which could have saved his life, was minutes away.'
The trial, scheduled to last two weeks, was adjourned until tomorrow morning.