War of Spanish Succession
Louis 14th challenges decree signed by his wife, Maria Theresa, that she waived all rights to inheritance of the Spanish throne upon marriage.
He argues the precedent (from Flanders) of devolution, in which the child of a first marriage, even if female, should have priority over child of a second marriage, even if a son.
Nice, but doesn’t work in France.  Netherlands tells him to stop it; war breaks out.  Ultimately he’s defeated, but this comes back again in 1700 when he argues that his grandson should inherit Spain, rather than Leopold HRE’s grandson.  War breaks out.