Seven people know the truth.

Being cut off from friends and family, being isolated, being told not to talk to anyone — is unfortunately a very well-documented aspect of abusive relationships. The trauma, psychological dynamics, and neuroscience behind these dynamics are real and have been studied.

1. What abusers often do: isolation, control, cutting off witnesses

Here are research-backed tactics that align exactly with what you report (for example, cutting you off from long-standing friends and family).

a) Isolation as a control tactic

According to the advocacy organisation Women’s Aid: “Controlling behaviour … is designed to make a person dependent by isolating them from support, exploiting them, depriving them of independence and regulating their everyday behaviour.” Women’s Aid
An article on domestic abuse explains: “Isolation is a powerful abuse tactic — abusers cut survivors off from friends, family, work and healthcare to gain control and make them dependent.” domesticshelters.org+1
Another piece summarises: “At the start of a controlling relationship, isolation tactics are so sugar-coated we might not recognise them for what they are.” NCDV

In your case, the pattern you describe—“never ever to talk to them again”, severing longstanding friendships, cutting out people who might support you—is classic isolation.

b) Power & control framework

The widely used “Power & Control Wheel” (developed by the Domestic Abuse Intervention Project) describes how abusers use a variety of tactics (emotional abuse, intimidation, threats, isolation, economic abuse, etc.) to maintain power and control. dvsn.org+1
You can view your situation through that lens: The abuser tries to remove external supports (friends, family, professionals) so they become the main (or only) contact in your life, thereby increasing your vulnerability.

c) Multiple tactics beyond physical violence

Abuse isn’t only about hitting or physical aggression. Psychological abuse, emotional manipulation, controlling behaviours are central. For instance:

A meta-analysis of abusers with narcissistic traits found that psychological IPV and cyber abuse are more strongly related to narcissism than physical violence. PMC
The mental health impacts of coercive control (a pattern of controlling behaviours) include PTSD, complex PTSD, depression and isolation. PMC+1

The fact you mention “professionals (Doctor, psychologist and Gendarmes in France)” and that many people who kneware being shut out indicates a concerted strategy of removing witnesses / support networks.

2. Why this happens: Neuroscience & psychological mechanisms

Understanding why the abuser does this — what’s going on in the brain, emotionally, psychologically — can help you see this as the abuser’s pattern rather than your fault.

a) Need for control, fear of losing power

Abusers often operate from a place of needing to feel in control, fearing abandonment, or believing they are entitled to dominate the relationship. The research on narcissism and abuse shows that trait narcissism (grandiose or vulnerable) is weakly but significantly related to intimate partner violence — especially psychological abuse. PMC
From a neuro-psychological standpoint, control allows the abuser to mitigate their own fears (of being exposed, of losing the partner) by limiting your autonomy. The result: you become more dependent, less likely to reach out, less able to corroborate or seek help.

b) Isolation amplifies trauma responses

When you are cut off from your support system, your brain starts to respond differently. Some relevant findings:

Isolation and the removal of social support increase long-term mental health risks (depression, anxiety, PTSD) in survivors of abuse. Human Options+1
The “Lonelification” paper describes how survivors’ lived experience of isolation acts deeply on their mental health and recovery. journals.sagepub.com
When you cannot compare your experience with outside reality (friends, family, professionals) the abuser’s narrative (denial, minimising, blaming) can take hold more easily, and your sense of self and reality can be undermined.

c) Severing relationships = weakening your “external reality check”

Having people who know you (your sister, best friend of 34 years, friends abroad, brother, wife of your brother) provides reality-checking, emotional support, witnesses. When an abuser succeeds in isolating you from those, you lose:

validation of your experience (someone who says “yes, I saw/heard that”)
emotional buffer (someone outside the relationship who affirms your worth)
leverage (you are less able to mobilise support for change or escape)

This is exactly what you described: people who “knew” all of this (sister, friend of 34 years, etc) and the abuser trying “his best to sever relationships with most of these people.” That is textbook abusive dynamic.

That agrees with the literature describing “the role of personal networks in cases of domestic violence” where researchers note that social networks often don’t just disappear but are silenced, undermined, or manipulated. arXiv

d) Trauma brain responses

When a person is subjected to prolonged abuse and isolation:

The brain’s threat/alert systems are activated (amygdala, HPA-axis). Over time this can lead to hypervigilance, anxiety, diminished ability to “think through” decisions clearly. Research links exposure to intimate partner violence with increased risk of PTSD and depression. PMC+1
The prefrontal cortex (in charge of decision making, impulse control) can be impaired by chronic stress, making it harder to act (e.g., escape or seek help) or process the situation clearly.

So: the abuser’s strategy of isolation doesn’t just remove your supports — it structurally weakens your ability to respond, process, and act.

3. Mapping your scenario to this framework

You listed several people: your sister (Angela), your best friend of 34 years (Jane), friends from Spain (Anne), France (Leanne, Nicky), your brother’s wife (Christine), your brother (Martin — no longer with you) and professionals (doctor, psychologist, gendarmes in France). You said 7 people knew about the strangulation (which is a serious event) and the abuser tried to sever the relationships with most of them and succeeded with most, telling you never ever to talk to them again.

Here’s how that maps to the model:

Witnesses/supporters: Having many people who were aware of the abuse (7 people + professionals) is very important. These are exactly the “external reality check” and support network that abusers fear.
Turning them off / cutting contact: By telling you not to talk to these people, forbidding contact, you are being systematically isolated. That reduces your ability to tell your story, get feedback, and act.
Preventing evidence and accountability: If the abuser can stop you communicating with people who knew, then the community memory of the events (e.g., strangulation) is minimised, making it easier for the abuser to deny or minimise what happened. This aligns with the “power and control” and “coercive control” models.
Undermining your autonomy: By cutting you off, the abuser increases their dominance, reduces your independence and increases your difficulty in seeking help or leaving.
Emotional/psychological consequences: You may feel even more alone, even more trapped, less able to trust your own judgement, which is exactly the trauma response the research warns about.

4. Why the abuser might pick those specific people

From the pattern: longstanding friends (34-year best friend), close family (sister, brother, brother’s wife), international friends (Spain, France) and professionals. These are high-value supports:

Long-standing relationships carry memory and credibility → they are potent witnesses.
Professionals (doctor, psychologist, gendarmes) carry authority and could intervene.
International friends are harder to reach or control centrally, so cutting them off prevents outside intervention or perspective.

So by removing or forbidding contact with these people, the abuser is reducing your ability to: communicate with those who care about you, coordinate support, receive help, maintain evidence of what has happened.

5. What you can take from this (for you)

Recognise the pattern: What you experienced aligns with documented tactics of abuse (isolation, removal of support networks, controlling communication). That means you are not imagining it, and it’s not your fault. The abuser is following a playbook, not reacting to you.
Re-establish connections wherever possible: If you can safely reach out to those people (sister, best friend, friends abroad) this can help you rebuild the “external reality check” and reduce your isolation.
Document what you can: Names, dates, witnesses, what happened (strangulation), who knew — these all matter. The more you have, the less plausible the abuser’s attempts at erasure become.
Work with professionals: You mentioned doctor, psychologist, gendarmes in France — if you can, involve a professional who understands coercive control (not just physical violence) and is trauma-aware.
Self-care and grounding: Isolation increases vulnerability to trauma responses (PTSD, depression, dissociation) so nurture your mental health: safe social contact, therapy, supportive networks, anchoring in activities you trust.