Proud of his religion and worried about its future, Chicago dentist Max Feinberg wrote a will with an unusual catch: His grandchildren wouldn't inherit a penny if they married someone who wasn't Jewish.

His decision led to family feuds, lawsuits, counterclaims and, on Thursday, a unanimous ruling by the Illinois Supreme Court that Feinberg and his wife were within their rights to disinherit any grandchildren who married outside the faith.

"Equal protection does not require that all children be treated equally ... and the free exercise clause does not require a grandparent to treat grandchildren who reject his religious beliefs and customs in the same manner as he treats those who conform to his traditions," Justice Rita Garman wrote in a ruling that overturned decisions by two lower courts.

One disinherited granddaughter had argued it was improper for a will to set up conditions that promote religious intolerance in people's marriage decisions or even encouraged couples to divorce.

"It is at war with society's interest in eliminating bigotry and prejudice, and conflicts with modern moral standards of religious tolerance," said Michele Feinberg Trull's brief to the Supreme Court.

The court's ruling was based partly on technicalities in the way this estate was arranged. The court did not provide a broad ruling on whether similar religious restrictions would be valid under other circumstances.