The brother of a House of Lords member has been declared unfit to plead over historical child sex offences he faces alongside the former Labour peer.
The charges against Lord Ahmed of Rotherham and two of his brothers, Mohamed Farouq and Mohammed Tariq, date back to the late 1960s and early 1970s.
All three were due to face a trial in the summer.
Mr Farouq would not be able to follow details from "truly ages and ages and ages ago", Sheffield Crown Court heard.
Judge Jeremy Richardson QC told the court he had reached the "unhesitating conclusion" that Mr Farouq, 68, of Worrygoose Lane, Rotherham, would not be able to instruct lawyers.
"I simply state for the purpose of underlining how long ago these offences are alleged to have occurred that Harold Wilson was the still the prime minister in his first period of office, President Lyndon Johnson was the president of the United States, and it was only in late 1968 that President Nixon was elected to office."
He said he was "testing my own recollection to the full" and cited events such as the assassinations of Martin Luther King and Robert Kennedy in 1968, as well as the Vietnam War.
"Such observations are made by me to reveal how long ago these allegations are said to have commenced."
The judge concluded: "Each of the experts is entirely satisfied that the defendant, Mohammed Farouq, is unfit to plead."
Lord Nazir Ahmed, 61, of East Bawtry Road, Rotherham, denies all the charges against him.
He is due to stand trial on 13 July but the date may be reviewed because of the coronavirus pandemic, Judge Richardson said.
Mr Tariq, 63, of Gerard Road, Rotherham, was also found unfit to plead. He and his older brother will face a so-called trial of the facts, with no verdicts of guilty or not guilty open to the jury.
None of the defendants were at the hearing on Tuesday. A further hearing date is due to be set next month.
Lord Ahmed resigned from the Labour Party in 2013.
Nazir Ahmed - serious sexual assault against a boy under the age of 11 and the indecent assault of the same boy; two counts of attempting to rape a girl who was under the age of 16. All charges relate to dates between 1971 and 1974.
Mohamed Farouq - four counts of indecent assault against a boy. One of these counts relates to when the boy was under eight, in the late 1960s.
Mohammed Tariq - two counts of indecent assault against a boy under 11.