The sexual offences committed against the teenagers have been described as "perverted in the extreme", with the abuse sometimes going on for days at a time.
The men used the girls, it's alleged, for their own gratification, but also took them to other places - normally hotels and guest houses - and to empty houses where they were abused by other men.
This abuse often took place with groups of men who paid money to the defendants for sex.
None of the money ever reached the victims.
The court was told that the men were "much older" than the girls and would have known that their victims were under-age. Therefore, the prosecution says that their actions were "intentional and persistent."