Which certificates to show family line?

[Trinidading3]

Can anyone enlighten me as to which certificates e.g birth, death, marriage do I need to show family line/entitlement to Land ....?
The thing is it's a Great Grand Aunt ..(no children no will) ....the line goes like this....son, dad,grandad, great grand dad, wife of great grandad (is the sister of the Great Grand aunt) ......

It's making my head spin.....anybody with the knowledge much appreciated......I'm thinking birth and death certificates for all the people involved... 🙃

And marriage where applicable

If I understand correctly the deceased is only related to you by marriage of their sibling. So you're not entitled to anything as not a direct blood descendant.

Actually you might be if sibling of GGA died before her sister (wife of GGF), and in turn her sister died before GGF and all died intestate. I think...

If I understand correctly, son is the direct descendant of the deceased's sister (assuming that the deceased's sister is grandad's mother). If that is correct and great grand aunt has only just died, there is an entitlement.

Who wants to see proof of entitlement?

I read it as sibling of someone who was married to GGF without being the parent otherwise OP would have put the GGM as the direct family member? Maybe OP can clarify?