This is a rather confusing way of stating the verdict.  The case was
concerned with the inheritance of Louis-Ferdinand's estate, which was
subject to certain conditions by virtue of a contract of 1938.  The
contract required the principal heir be offspring of an equal marriage
and, if married, himself married equally.  Lower courts rejected the
clause as invalid, the High Court upheld it.

A press release by the Federal High Court can be found (in German) at
http://www.jura.uni-sb.de/Entscheidungen/Bundesgerichte/BGH/zivil/erb...

Here is my rough translation of that text.

The Federal High Court (Civil section) had to decide on the validity of a succession
in the house of Prussia as set forth in a succession contract of 1938.  At that time,
Wilhelm of Prussia, ex-Kronprinz, with the participation of ex-Kaiser Wilhelm II, had
named his second son Louis-Ferdinand prince of Prussia (d. 1994) as first heir (Vorerb).  
After his death his eldest son (unborn in 1938) was to be the next heir (Nacherb), or,
should that son not survive Louis Ferdinand, in his stead his eldest male offspring; in
the absence of male issue his eldest brother (or in his stead his sons).  The contract,
however, made one exception to the rule on the succesion of the next heir: any son or
grandson of Louis-Ferdinand was ineligible to inherit if he were not the issue of a
marriage made in accordance with the house laws of the house of Brandenburg-Prussia, or
if he was in a marriage not in accordance with said laws (so called ineligibility clause).

The lower courts (high court: Stuttgart, court: Hechingen) held that clause to be immoral
or in any case incompatible with "good faith" (Treu und Glauben).  It violates in particular
the protection of the freedom to marry (art. 6 of the Constitution) and ran against
the prohibition on discrimination based on descent and origin (art. 3, par. 3 of the
Constitution). But since the High Court of Bavaria, in another case, had held as valid
a clause which excluded from the succession of a princely house those who married without
the consent of the prince as head of the house, the Stutgart High Court referred the Prussian
case to the Federal High Court.

The 4th civil chamber holds the clause in question to be valid.  Given the testator's
freedom protected by art. 14, par. 1, sentence 1 of the Constitution, only in exceptional
cases can infringements of the rights of offspring in testamentary dispositions lead
to the disposition being immoral and therefore void.  This can happen, when there is
a serious assault on the protected area of basic rights of the offspring, and when
the dispositions aim to restrict the freedom of the concerned in their most personal
decisions or to demean their human dignity.

The Federal High Court could not establish that the disputed clause had as goal to
intervene in the choice of a specific marriage partner or to demean the children
of a marriage deemed unequal in the eyes of the nobility.  Rather, a suitable
successor had to be found for an inheritance shaped by family traditions.  The
testator saw that successor in the eldest male offspring who represented the family
tradition, as it involves descent, by his descent and (if he was already married on
the death of the first heir) by his marriage.  Such a goal is protected by the freedom
to testate.  Against it the infringement of rights is not so important as to make
the clause immoral and thereby void.  The legitimate rights of the offspring are
already protected through the reserve portion which by law secures half of the
inheritance for them.

The case was sent back to the Hechingen court for clarification of certain facts
which are material to the case as a consequence of the clause.

Decision of 2 December 1998, IV ZB 19/97
(the press release is dated Dec 17).

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  Francois R. Velde
  http://www.heraldica.org/