what is the dialectical process of history?

Answer 1

The observer (writer) and the participant

Answer 2

The most famous example of a dialectical process
of history is Dialectical Materialism; which is the
philosophical basis of Marxism. DM is an ideological
system that results from a synthesis of dialectics
and materialism (ie. historical materialism).
.
Thus DM asserts that history is the product of class
conflict, and this on-going struggle between the
classes expresses the ideas of thesis and its anti-
thesis as they meet in battle, finally merging into
a greater synthesis that incorporates both elements.
.
Of course, this new synthesis then become a new
thesis that gives rise to a new antithesis, eventually
leading to yet another . . . synthesis! :)
And so on and so forth.
.
Actually, Marx "borrowed" most of these ideas from
a previous philosopher, called Hegel, whose dialectics
were intended to explain the development and
growth of human history in the most general, and
even universal, sense.