Tal Shava

The Tal Shava were a military group within the Romulan Star Empire.

This organization within the Romulan military was controlled by the Star Command's Pacification Command division. 

Apocrypha
The unpublished Last Unicorn Book The Dominion War: Fires of Armageddon mentions the Tal Shava who were called the Imperial Marines and were the largest of the elite units within the Star Empire. They were noted as experts in getting a foothold and conquering enemy controlled planets.