In 1922, the Landmandsbank, Scandinavia's largest bank failed and had to be bailed out by the Danish government. It was quite a mess....the bank and it's directors had lied about assets, been involved in stock swindles, there was embezzlement, missing financial records, etc.
Prince Carl and Princess Ingeborg of Sweden, among other members of royalty were stock holders and they lost the majority of what they had invested. And what they invested was the majority of what they themselves had. They had to eventually give up the huge home in which they lived and moved into a still spacious, but less expensive to maintain flat. Their children, particularly Margretha and Carl were the ones most affected in the long term with Martha and Astrid eventually finding more financial security in their marriages. (No, I am not suggesting that they married for money. lol)
Prince Axel of Denmark (husband of Margretha of Sweden) also lost a fortune in the Landmandsbank scandal. However, his father Prince Valdemar did help him out financially from time to time.
Axel's oldest brother Prince Aage, Count af Rosenborg apparently had his hands all mucky from his involvement in Landmandsbank and supposition had it the only thing that saved him from criminal charges and imprisonment was that Aage joined the French Foreign Legion right after the bank collapse.
When Countess Ruth married Prince Flemming in 1949, she was astonished at the lack of funds she married into and even commented as such in later years. Fortunately for Prince Flemming, the family of his new wife was wealthy.