My great great grandparents (Moses Josua and Betty Hertz) got married about
1800 in Altona, which is also where all their children were born (all births
were pre-1820).

Searching in the Hamburg archive/Talmud Thora proved fruitless because - as
they explained to me - during that time period, Altona was part of
Denmark... and the corresponding records are not in Germany (Hamburg).

I would be very grateful if some of you, experienced with family research in
Denmark, could suggest where I might look to find Altona Jewish records from
ca 1720-1820.

Thank you.

Friendly regards,
Alan Ehrlich
Geneva Switzerland