An emaciated boy was the subject of a campaign of "incomprehensible" cruelty by his mother and stepfather before he died, a court has heard.
Four-year-old Daniel Pelka's condition was likened by a doctor to that of a concentration camp victim.
He was deliberately starved over several months before being beaten to death at his Coventry home in March 2012, Birmingham Crown Court heard.
Mother Magdelena Luczak, and her partner, Mariusz Krezolek, deny murder.
The pair, who came to Britain from Poland in 2006, also deny causing or allowing his death, but have both admitted a charge of child cruelty.
The court heard claims that the youngster was "imprisoned" in a bedroom, which had no door handles, and force-fed salt.
Opening the case for the prosecution, Jonas Hankin QC alleged that text messages provided compelling evidence of Ms Luczak and Mr Krezolek's guilt.
Daniel's mother is alleged to have said: "He's temporarily unconscious as I nearly drowned him. I am having some quiet time."
Mr Hankin told the jury that four-year-old Daniel, who was found to have suffered a brain injury, was unconscious when a text message was sent from Ms Luczak to Mr Krezolek at 16:34 on 2 March.
The message, translated from Polish, is alleged to have read: "He'll get over it by tomorrow.
"There is no point to stress ourselves out and to call an ambulance because that will cause proper problems."
Daniel was pronounced dead at University Hospital Coventry after a 999 call was made by Mr Krezolek at 03:07 on 3 March.
A post-mortem examination found he had "groups of injury" over his body.
Mr Hankin told jurors that a gastroenterology expert found Daniel was "extremely emaciated" and had a low body mass index.
He said the jury would hear the level of Daniel's malnutrition could have happened over three months, but is likely to have occurred over a longer period.
The prosecution alleges that at some point between the evening of 1 March and late morning the next day, Daniel was subjected to a "violent assault in his own home by one or the other, or both, of the defendants".
"Irrespective of who landed the fatal blow, each bears responsibility for his murder," Mr Hankin told the court.
"This act of cruelty and violence was not an isolated incident.
"Leading up to his death, he was subjected to a campaign of incomprehensible and escalating cruelty."
The trial continues.