The 25-year-old insisted she had been raped or attacked but after a five-week trial at Southwark Crown Court a jury of six men and five women took eight hours and 45 minutes to find her guilty of perjury and perverting the course of justice.
Judge Nicholas Loraine-Smith ordered psychiatric reports and referred to Beale's "attention-seeking, which is what this case is all about".
He told her: "You have been convicted of all of these matters. They are very serious indeed, counts one to four most particularly.
"Somebody went to prison for a long time as a result of your perjured evidence.
"I am going to remand you in custody and I will be fully informed of your true psychiatric state when you return in August."
Beale made her first complaint on the morning of 26 November 2010, when she told police she had been raped by Mr Cassim the previous night.
Jurors heard the 37-year-old Somalian came to the UK in 2002, aged 23, after a short stint living in Sweden where he also served in the military as part of the peace-keeping corps.
Beale and Cassim accepted that he offered her a lift home which she accepted.
But he stopped the car and Beale directed him to a discreet alleyway.
"We drove for about ten minutes and while we were in the car we were talking and then she came and gave me a rub on my knuckles, my hand," Mr Cassim said.
"She was asking me kind of questions, whilst rubbing my knuckles, asking, obviously about sex."
He added: "I said 'Are you sure?' and she said yes - I asked three times 'Are you sure?' - and said OK."
Cassim said they got out of the car.
"Then all of a sudden, after about three yards she told me to pull off my underwear."
Cassim was tried for rape at Isleworth Crown Court in December 2011.
A retrial then took place in January 2012 in front of a fresh jury and he was jailed for seven years.
In a victim impact statement Beale described the 'devastating' effect the "rape" had on her.
"I feel that any sentence he receives will never reflect the life sentence that he gave me," she said.
Cassim served two years because of the 'grave injustice' before he was released.
Beale then complained to police she was the victim of two sexual assaults in July 2012, one of which involved "sexual violence of a most serious kind".
She later complained to police she was groped by a stranger, Noam Shahzad, in a pub in July 2012, before he took part in a gang rape on her.
Beale even injured herself to back up her claims that she had been assaulted with barbed wire.
Shahzad skipped bail and fled the country after being charged with sexual assault.
Beale then fabricated similar allegations against six other men in 2013.
She claimed two strangers sexually assaulted her close to her home in Ashford, Middlesex, before she was put through another gang rape attack by four others two months later.
Two of the men identified by Beale - Luke Williams, 28, and 25-year-old Steven McCormack - were arrested and interviewed but never charged.
She claimed Shahzad groped her at The Windsor Castle pub, in Hounslow, before the same man took part in a sickening gang attack in the car-park of a nearby medical centre using barbed wire.
Crime scene examiners recovered a number of items from a small gap between the east side of the centre and the brick wall perimeter.
Among those was a wire basket containing a small amount of Beale's DNA along with one of her earrings.
Beale claimed the sample was left as she urinated there but prosecutors claimed the basket was used to cause the "self-inflicted" injuries.
"The group of men did not exist," said prosecutor John Price, QC.
Beale reported another serious sexual assault, this time by two men, on September 2, 2013 which she claimed it had happened five days earlier outside of her home.
Although neither alleged attacker was ever identified she said one of the pair was also involved the previous attack in July.
Again the entire incident was "a grotesque invention".
Beale reported another attack in Feltham, west London, two months later, on 17 November.
"She described a gang rape at night in a street of the most appalling kind,' said Price.
"She alleged that she had been raped one after the other by four of a group of eight men, and she identified two of them as Luke Williams and Steven McCormack.
"Both of those men were arrested by police later that same day."
Beale had spent the evening with Williams and others at a house party, and that she had left willingly with him to go and get alcohol and cigarettes.
She claimed he took her to a garage where he arranged for a McCormack and others to attack her, and that he was armed with a machete.
In the days before the alleged assault, McCormack said Beale had threatened to get him into trouble with the police.
"Each of those reports made by Jemma Beale to the police is alleged by the prosecution in this case as being entirely false," said Price.
"She had not been raped.
"Nor had she been sexually assaulted on any of these occasions."
She was arrested in June 2014 and eventually charged in March of last year.
Beale told the court she had been bullied at school for being fat and she insisted she was a lesbian and said she had been in several relationships with women.
"I'm not going to go to a man I don't know and ask him for sex,' she insisted, adding: 'I ain't bisexual at all."
Mr Price warned jurors to be "under no illusion" that Beale's memory or intellect were in any way deficient.
She claimed to have been taught a technique for suppressing traumatic memories but later conceded in the witness box they were not "locked away".
"What she says by way of explanation for her inability to recall such obviously important and startling incidents in her own life is that it is boxed away," he said.
"It is bogus. It is psychobabble."
Beale, of Bedfont, Middlesex, denied four counts of perjury and four counts of perverting the course of justice but was convicted by the jury.
She was remanded in custody ahead of sentence at Southwark Crown Court on 24 August.
