Getting berated and disrespected by colleague, no HR department

Hi all,

I am hoping for some practical advice here as I am not good at navigating these issues.

I work in a highly technical field and I'm at the senior level. This other senior employee who has been at the company for 10 years is known to be abrasive but "that's just how he is" and apparently he enjoys the "debate" with others, or playing devil's advocate. This was the response I was given by my direct manager when I first mentioned this coworker seemed to not enjoy working with me.

Since then he has begun to make a habit of calling me randomly in the day where he 1) raises his voice (yelling) 2) demands that I justify my work , but then cuts me off while I'm speaking 3) accuses me of being incompetent, direct quote from the last one was "you make terrible decisions" and he laughed shaking his head in disbelief. He will also do this in front of others on his team. He also chooses to send emails to me and cc other senior employees to rip apart any notices or updates I send out.

I have considered that perhaps my work performance may be an issue but I can't see how. The reasons I have this belief is that I don't work on the same team as this person, I don't report to him, and I work closely with 3 others with whom I make every decision and plan projects. So in other words he doesn't even know if what he's accusing me of being "wrong" is even my work.

I dont know what to do, I do not have it in my personality to be confrontational. I told him in the last call that I didn't understand why he was constantly putting me on the spot for things that aren't my job, or that have nothing to do with other business units and he got quiet and we finished the meeting and ended the call with an awkward tone. I had raised my voice for the first time towards him in this meeting, and there was another employee there.

Its a family owned business and all of us pretty much ultimately report to the owner, he has a very high opinion of this other employee as his work is highly specialized and he's very good at his job.

Im not trying to make this a gender thing but for what it's worth I'm the only senior level female in the company. He does NOT go this far with the others.

Please help me