Legion

Legion refers to a large grouping of soldiers. It was generally the equivilant to a corps.

The largest ground force unit in the Breen military was referred to as a legion or hon or hareh in Breen. (LUG RPG: )

The Romulan Ground Forces legions were called barhet'val and comprised of between 80,000 to 100,000 soldiers. They were commanded by a high ranking general. 

A legion from the Romulan Star Empire was used during the Liberation of Nthony C. It was sufficient along with the air and space superiority to be able to defeat the Dominion's presence on the planet within a few days and further secure Nthony C following its occupation.