One theorem named for this man states that the number of subgroups whose order has prime divisor p is equal to 1 mod
The Abhyankar problem uses structures named for this man in order to show the existance of Galois group for a projective curve.  The Alperin-Braer-Gorenstein theorem is about classifying structures with a property named for this man that are quasi-dihedral. Structures named for this man are central to Frattini's Argument. One theorem named for this man states that the number of subgroups whose order has prime divisor p is equal to 1 mod p. Those structures are always conjugate to each other, implying that when one of them is normal, it is also unique.  His namesake theorems state that for a group of order p to the n times q, specific subgroups exist. FTP, name this man who names particular p-subgroups, a partial converse to Lagrange's theorem.
The Abhyankar problem uses structures named for this man in order to show the existance of Galois group for a projective curve.  
Peter Ludwig Mejdell {Sylow}