Grand Admiral a naval rank in one of the highest in the several European navies that use this system, what system are they using?
Grand admiral Grand admiral is a historic naval rank, the highest rank in the several European navies that used it. It is best known for its use in Germany as "Großadmiral". A comparable rank in other navies is that of fleet admiral.
Two-star rank An officer of two-star rank is a senior commander in many of the armed services holding a rank described by the NATO code of OF-7. The term is also used by some armed forces which are not NATO members. Typically, two-star officers hold the rank of rear admiral, counter admiral, major general, or in the case of those air forces with a separate rank structure, air vice-marshal.