triumvirate

1. A council of three magistrates ruling jointly; specifically, the First Triumvirate (60 or 59 – 53 B.C.E.) or the Second Triumvirate (43 – 33 or 27 B.C.E.); the office of a triumvir (“one of such magistrates”), or of the three triumviri.
2. Any group of three joint rulers.
3. Any group of three people regarded as significant in some way; also (rare), a group of three things; a trio. (figuratively)

الجمع triumvirates