What is my children's Nationality status?

[stantheman457]

Hi.
Hopefully, somebody can help me answer the following.
I have three adult children, all of whom live in Germany.
I am British English by birth. My whole ancestry as far back as it can be traced (a couple of hundred years) is also British.
The mother of my children is a German national, also with long traceable ancestry.
I was a serving soldier in Germany from 1981 through to 1987, and then returned to Germany in 1990.
I left the army in 1993 but stayed in Germany until 2004.
The first of our children was born in Germany in 1987. We registered the birth with the German authorities and a German birth certificate was issued. Note: I was a serving soldier at this time.
The second of our children was born in the UK in 1989. I was still serving in the Army. This one has a UK birth certificate.
The third child was born in Germany in 1996. I was working within the German economy at this time. This one also has a German birth certificate.
All three of my children wish to be identified as having dual nationality.
So my question is:
Are they all entitled to UK passports.
Currently, they all have German ID cards and German passports.

Any answers (correct ones of course) are greatly received.

Many thanks and kind regards.

[IndiMarshall]

Your children are British by descent as you are British by birth. I would imagine that they are eligible for UK Passports...

[vinny]

Were/are you married to the children's mother?

[stantheman457]

Hi - Thanks for the initial answers.

Yes - married to their mother when all three of my children were born.
Does it make a difference?

Many thanks in advance

[vinny]

Yes. Prior to 2006, marriage made all the difference. It means that IndiMarshall was correct.