From Longman Dictionary of Contemporary Englishdo something of your own free willdo something of your own free willFREE TO DO WHAT YOU WANTto do something because you want to, not because someone else has forced you to He came of his own free will. → free will
Examples from the Corpus
do something of your own free will• Bronson gave us his confession of his own free will.• For all men serve him of their own free will.• Her mouth opened of its own free will to his playfully probing tongue, welcoming the invader.• I came back of my own free will on Friday, and went to the game yesterday.• I say this of my own free will.• She was placed in a safe house but later returned to the coven of her own free will.• To some extent, adults can choose of their own free will whether to deal with their grief or not.• Without any reason he left the Firm of his own free will and went to live in Brighton. 