Which language is the language of Oceania, a totalitarian state of the dystopian novel by George Orwell?

Newspeak is the language of Oceania, a fictional totalitarian state and the setting of the dystopian novel Nineteen Eighty-Four (1949), by George Orwell. To meet the ideological requirements of English Socialism (Ingsoc) in Oceania, the ruling Party created Newspeak, a controlled language of restricted grammar and limited vocabulary, meant to limit the freedom of thought — personal identity, self-expression, free will — that threatens the ideology of the régime of Big Brother and the Party, who have criminalized such concepts into thoughtcrime, as contradictions of Ingsoc orthodoxy.

In "The Principles of Newspeak", the appendix to the novel, George Orwell explains that Newspeak usage follows most of the English grammar, yet is a language characterised by a continually diminishing vocabulary; complete thoughts reduced to simple terms of simplistic meaning.