As I see it, Slovak historians claim Great Morava as first Slovak state, while Czech and other foreign historians think it was Czech/Slovak-Slavic state, or have some quite oposite views:

"Samuel Timon Jesuit priest claimed ("Imago antiquae Hungariae" [The Description of Old Hungary]) that the Hungarians by destroying Greater Moravia, had liberated the Slovaks from the Moravian yoke."

"Russian historian George Vernadsky asserted that Great Moravia is the legacy exclusively of the Czechs."

"Czech historian Václav Chaloupecký asserted that Slovaks are Czechs by origin but their almost 1000-years existence in the Kingdom of Hungary led to their separation from the Czech nation."

Interesting question is also were Constantin and Methodius Greeks or Slavs? Official history think they were Greeks.

Monument in Belgrade