A teenager described how she was "branded" with a heated hairpin by a man accused of raping her.
The 19-year-old said she was 12 and "tiny" when Mohammed Karrar abused her after an argument at her home in Oxford.
She told the Old Bailey Karrar bent the hairpin and put an M on her bottom - a mark which lasted three years.
She said: "After heating it up for a little while, he stuck it on my bum. It was M for Mo and he said I belonged to him. He was branding me so people knew I was his."
The woman said she was abused by Karrar and his brother Bassam for over a year before being forced to have sex with other men.
Afterwards, Karrar would scrub her hard in the bath and call her a "dirty bitch", she said.
On one occasion, she threatened Karrar with a lock knife after he raped her in a bathroom. Her punishment was being hit across the head with a baseball bat and assaulted with its metal handle, she told jurors.
"At the time, I thought he loved me and it was a mistake he made. I thought it was my own fault, that I threatened him with a knife," she added.
Nine men from Oxford deny 51 counts including rape, trafficking and organising prostitution between 2004 and last year, involving six under-age girls.
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.