Young girls were sexually exploited by a group of men who subjected them to depravity and perversion, a court heard today.
Six girls were used by men, including nine defendants from the Oxford area, the Old Bailey jurors were told.
One victim was only 12 when she was forced into prostitution.
The court clerk was allowed to sit as he took half an hour to read the charges.
Noel Lucas QC, prosecuting, said: "This case involves the sexual exploitation of children - young girls - by groups of men in the Oxford area."
The men deny the 51 counts, including rape, trafficking and organising prostitution between 2004 and last year.
The accused include two sets of brothers, Akhtar Dogar, 32, and Anjum Dogar, 30, and Bassam Karrar, 32, and Mohammed Karrar, 38.
The others are Kamar Jamil, 27, Zeeshan Ahmed, 27, Assad Hussain, 32, Bilal Ahmed, 26, and Mohammed Hussain, 24.
The trial is expected to last until April. The defendants are all in custody.
Mr Lucas added: "The defendants, and others not before the court, used and abused the six complainants persistently over long periods of time, sometimes in groups, for their own sexual gratification and the sexual gratification of others.
"The depravity of what was done to the complainants was extreme."
He told the jurors that the details of the case would make them uncomfortable.
Mr Lucas said the men "actively targeted vulnerable young girls from the ages of 11 or 12".
Sometimes the abusers would come across them while they were playing truant or out drinking.
Mr Lucas added: "There is evidence that the men deliberately targeted children who were out of control.
"They also targeted children who had been sent to live in care homes for precisely that reason. Some of the girls had been sexually exploited by other men, before they encountered these defendants.
"Some girls already being abused by the group were tasked to find other girls for the group."
He said the girls were chosen because they had troubled upbringings which made it less likely that anyone would have parental control over them or be looking for them.
"The girls were then groomed in a variety of ways such as being given gifts or simply by being shown the care and attention they craved," said Mr Lucas.
"The attention lavished on the girls at the outset was entirely insincere. It was merely a device to exploit their vulnerability.
"Having secured their confidence the men would ply the girls with alcohol and introduce them to drugs such as cannabis, crack and sometimes heroin."
The youngsters would become addicted to the drugs and this made them even more dependent on the men who exercised extreme physical and sexual violence on them.
The men threatened to harm the girls or their families should they ever flee the group, Mr Lucas said.
"It was in these ways the men came to exercise control over the girls who, because of their previous experiences and disturbed home lives, were likely to subject themselves to sexual exploitation and abuse," he said.
One of the complainants described being in a "living hell" during the period of alleged abuse from May 2004 to early 2012, the court heard.
Many of the sexual acts committed on the girls were "extreme in their depravity", the prosecutor said.
The girls were often taken to guest houses or empty private properties in Oxford, some of which were used solely for abuse, Mr Lucas said.
Men would also travel from Bradford, Leeds, London and Slough to pay to have sex with the girls in appointments arranged by the defendants, the court heard.
Mr Lucas added: "The evidence in the case will show that these defendants and the others with whom they operated showed the complainants little or no human decency or consideration.
"Their conduct towards these very young and vulnerable girls was with total disregard to any moral inhibition as to their conduct."
One of the alleged victims befriended "a group of Asian men", including three of the defendants, when she was aged 12, the court heard.
The youngster, who cannot be named for legal reasons, smoked cannabis and often played truant, making her an "ideal target" for the group, Mr Lucas said.
They bought her gifts such as perfume and provided her with cannabis and cocaine in an "act of grooming", Mr Lucas said.
The men later took the youngster to various guest houses and hotel rooms, where they had sex with her together and on their own, jurors were told.
"If she refused to go they would threaten her, saying that they would burn her house down and her brother would be burnt alive," Mr Lucas said.
"On the way the men told her that she had to make them happy and not cry."
They would also arrange for other men to pay to have sex with her, Mr Lucas said.
Men would often travel from Bradford, Leeds, Slough and London to have sex with her, "the vast majority being Asian and the rest black", the prosecutor said.
The men would take photographs of her during sex on their mobile phones and called her names such as "dirty girl", the court heard.
She would have sex with two or three men at the same time, most of whom refused to wear condoms, Mr Lucas said.
She would also see other drugged and emaciated girls in the houses, but they were often kept separate, jurors were told.
"It got to the stage where she just got 'wasted' and let them get on with it for fear of getting a 'kicking'," Mr Lucas said.
Prosecutors claim that three of the defendants - Kamar Jamil, Akhtar Dogar and Anjum Dogar - were involved in organising the abuse of the girl. A fourth defendant - Assad Hussain - is alleged to have been one of the men who paid to have sex with her knowing she was under-age.
"By organising this enterprise the first three defendants were arranging or facilitating child prostitution," Mr Lucas said.
The girl described being away from home for up to eight days, the court heard.
Mr Lucas said: "She frequently caught chlamydia. She was often covered in bruises and burns where the men had stubbed her with cigarettes.
"She began to self-harm as a result of the trauma. She describes the period as a 'living hell'."
The girl's mother described her daughter as "sweet and innocent" until her behaviour changed from March 2005 when she was 13.
She became "cocky, angry, confrontational and aggressive" and began self-harming, claiming "it takes away the hurt", the prosecutor said.
The court heard that in February 2006 the girl reported to police that she had been held against her will by two Asian men.
She claimed they had forced her to snort cocaine and left her in an unconscious state, Mr Lucas said.
Then, in September 2006, the girl told police she had had sex with one of the defendants - Akhtar Dogar - and another man in a park in exchange for drugs.
"She explained she was sick of it all and that she hated them and all the things they do to her," Mr Lucas said.
The girl was examined by a doctor who found injuries consistent with "forceful oral sex", the court heard.
Dogar was interviewed by police about the allegation on September 13 2006 but denied rape, suggesting the girl had mistaken him for another Asian male, Mr Lucas said.
Jurors were told the girl decided shortly after her 15th birthday that the abuse had to stop.
Mr Lucas added: "She threw her telephone away, stopped taking drugs and went back to school. The men continued to hound her, but she was able to resist."
The trial was adjourned until Thursday.