A type of historical analysis advocated by the eminent French philosopher Michel Foucault.
Genealogy, in Foucault's view, does not entail a search for origins, nor does it reveal a linear unfolding of events; instead, the genealogical method cultivates a non-continuous view of history and explores diverse lineages of descent.
Genealogy draws from subjugated knowledges, a term designating two distinct types of learning: erudite studies peripheralized by grand theoretical perspectives; and "local memories", "incapable of unanimity", so particular and unsystematized as to be disqualified from the academe altogether. What unites these two disparate knowledges is that they carry "the memory of hostile encounters": that is, they are concerned with power struggles, a central concern for Foucault.
Thus, for Foucault, genealogy is not disinterested: it restages again and again a single drama, endlessly repeating the play of relationships of power and domination.
The quotations in this node are taken from "Two Lectures" (in Power/Knowledge: Selected Interviews and Other Writings, 1972-1977) and "Nietzsche, Genealogy, History" (in The Foucault Reader, edited by Paul Rabinow), though my thinking about Foucault has been influenced by his whole oeuvre.