Where does “Madrid” come from?

Madrid comes from Spanish Madrid, whose origin is unknown.

Ancestry of “Madrid”, step by step

Step	Language	Word	Meaning
1	Spanish	Madrid	—
2	Latin	mātrīx	—
3	Latin	māter	—
4	Ancient Greek	ἄρχω	To begin; To lead, rule, govern, command; To be...
5	Proto-Indo-European	h₂ergʰ-	to begin; to command, rule; to begin, rule,...