[Sherman Logan]

Before the outbreak of the war, Hitler's new Third Reich had created the largest German-speaking nation in European history.

Depends on how you define "German-speaking" and "nation."

The Holy Roman Empire of the middle ages was at various times considerably larger than the 3rd Reich in 1938. But it wasn't really a nation and wasn't all German speaking.

The German Empire of 1914 couldn't have been much smaller in area than Germany in 1938. But I haven't been able to find exact numbers.

[KC_Lion]

The Holy Roman Empire of the middle ages was at various times considerably larger than the 3rd Reich in 1938. But it wasn't really a nation and wasn't all German speaking.

It wasn't Holy, It Wasn't Roman and It wasn't an Empire.