It matters to know it

I hope you answer this little puzzle

is the following sentence correct grammatically and linguisticly and is there any other mistakes?

please, comment on the use of the relative pronoun" of which"

 Copious unsigned complaints, I knew, were lodged against him at the Country Council, the establishment of which was accompanied by the proliferation of such anonymously penned complaints.

thank you

Hi,
Fisrt, thanks so much for your being helpful

second, i'll try to answer your inquiries about the meaning of what i have written before
But, please note that  it was a short piece of a story written in Arabic and as a translator i translated it into English .Since I'm not a native speaker of English, I resorted to ask trustworthy experts

well,
1- the "Country Council",in some of the Arab countries ,consists of a group of the village's representatives that manages,among other things, its social, economic and educational issues.And this coinage is acctually mine since in English I donot think there is an equivalent for it.

2-the phrase"of which" refers to the council.

3-Unfortunatly, the complaints are the same and I sense a redundance here but it was so in Arabic
For this, I may suggest to split the sentence into two parts as follows:

"Copious unsigned complaints, I knew, were lodged against him at the Country Council. Following the council's establishment , the number of such anonymously-penned complaints swelled."

Thank you once more for both your time and effort & I'd like to await your helpful feedback

I'm quite with you that the order is not ok.But, I have an inquiry

would not it be vague to repeat the word council? it may seem as if there are two councils

am i right?

OrcaDeen

I'm quite with you that the order is not ok.But, I have an inquiry

would not it be vague to repeat the word council? it may seem as if there are two councils

am i right?

Thank you for your interest to share us

But, your sentence may mean that the main concern of the topic is the council while it is really not

And by deleting the preposition "at", this ignores that the complaints were lodged to that council

Also, the past perfect tense in "had been" may express a very far incident that was finished long ago and doesnot express the sense or continuation in the past since the complaints have been heavily lodged in large numbers

Lastly, Thank you so much