Romulan Star Empire

2370s

DS9 S07E14 "Inter Arma Enim Silent Leges"
(Also appears in TNG S02E11 "Contagion" but the below is a better view)

Read more on Memory Alpha

 
DS9 7x16 Inter Arma Enim Silent Leges - Romulan.png

Variations

 TNG S03E10 "The Defector"

TNG S03E10 "The Defector"

 
TNG 6x14 Face of the Enemy - Romulan 2360s Variant.png
 
 Symbol variant TNG S06E14 "Face of the Enemy"

Symbol variant TNG S06E14 "Face of the Enemy"