The only son and younger child of Prince Maximilian, Margrave of Baden and Princess Marie Louise of Hanover, Berthold married his second cousin Princess Theodora of Greece and Denmark, daughter of Prince Andrew of Greece and Denmark and Princess Alice of Battenberg, on 17 August 1931 in Baden-Baden.

His bride was also his second cousin, through Christian IX of Denmark.

The couple had three children:[3] He was conscripted as a soldier into the army of the Wehrmacht, but served only briefly and was exempted from military service in 1940 after being injured in France.

He was in a car driving with his son when he suddenly died from an acute health issue, probably a heart attack.

He was succeeded as titular margrave and head of house by his son Max.