Britain's Supreme Court Wednesday ruled in favor of a German heiress seeking to protect her considerable fortune from her ex-husband — a decision that gives new strength to prenuptial agreements in England.

The ruling marks a potential turning point in the legal battle over prenuptial agreements in England, where courts have generally refused to recognize them as valid, binding agreements.

Nicholas Phillips, the president of the Supreme Court, said the judges decided by an 8-1 margin to let stand an earlier Appeals Court ruling that the prenuptial agreement in this case was fair and should be applied.

It is a victory for Katrin Radmacher, 40, a paper industry heiress with a fortune of at least 55 million pounds ($86.5 million), and a defeat for her ex-husband, Nicolas Granatino, 39, a former investment banker who had been seeking a greater share of her wealth than had been spelled out in their pre-nup.

The case was complex: Radmacher is German, her ex-husband is French, but they married, lived and divorced in England. The prenuptial agreement was signed at Radmacher's father's insistence in Germany, and would have been recognized in both France and Germany, where pre-nups are commonly upheld.