Ash heap of history

The phrase "ash heap of history", is a derogatory metaphoric reference to oblivion of things no longer relevant.

In 1887 the English essayist Augustine Birrell (1850–1933) coined the term in his series of essays, "Obiter Dicta": that great dust heap called 'history.' 

A notable usage was that of the Russian Bolshevik Leon Trotsky referring to the Mensheviks: "Go where you belong from now on – into the dustbin of history!" as the Menshevik faction walked out of the All-Russian Congress of Soviets on 25 October 1917 in Petrograd.

In a speech to the British House of Commons, on 8 June 1982, U.S. President Ronald Reagan later responded that "freedom and democracy will leave Marxism and Leninism on the ash heap of history".

Similar expressions are into oblivion", "fall into oblivion", "drop off radar", "fall off radar". Lethe, in Greek mythology, a river of oblivion, gave rise to the Russian expression of the same kind: "sink into Lethe" (кануть в лету).