'which subjected him' is a correct and usable part of a sentence in written English
You can use it to refer back to a previously referenced event or situation that has caused the current situation. For example: John had been working long hours for months, which subjected him to extreme fatigue.
People close to Mr Prokhorov say that Vladislav Surkov, the Kremlin's chief ideologist, told him which subjects he could campaign on and nominated snoops to keep an eye on him.But Mr Prokhorov had his own ideas.
He called the telephone company, which then subjected him to a number of questions.
Accustomed as the midfielder is to operating on the right of the defence, he has no experience of the suffering to which Ronaldo subjected him.
Had any of those great champions swallowed the insults Haye spewed before the fight; had they seen an opponent wear a T-shirt showing the severed head of a member of their family; and had they promised to punish that opponent for it, the thrashing to which they subjected him would have made onlookers cringe.
He said: "It's a crime against women which subjects them to the most intimate personal violation".
To minimize the risk that another general might attempt to challenge him, Caesar passed a law which subjected governors to term limits.
To announce what was already obvious, he did not hold a news conference, which would have subjected him on the spot to annoying questions from the reporters charged with covering him.
He speaks of beatings and other forms of physical torture, and of the extreme psychological pressure to which his jailers subjected him to force a confession, including mock executions and threats to his family.
At such times it had been Wendy's custom to take him out of bed and sit with him on her lap, soothing him… and when he grew calmer to put him back to bed before he quite woke up, so that he should not know of the indignity to which she had subjected him.
Bird surmises that Grainger's fascination with themes of punishment and pain derived from the harsh discipline to which Rose had subjected him as a child.
