Crassus, a member of the First Triumvirate and known to be the richest man in Rome, more eager for glory and riches and then decided to invade the United Party without the formal consent of the Senate. Rejecting an offer of help from Artavasdes II King of Armenia to use its territory to invade the Parthian kingdom, Crassus marched his army straight through the desert of Mesopotamia. His army eventually met with the forces of Surena in the city of Carrhae, now Harran. Despite being heavily outnumbered, the cavalry of Surena fully overcame the Roman heavy infantry, killing or capturing nearly all the Roman soldiers. Crassus himself was killed after negotiations for a truce were likely violent. His death put an end to the First Triumvirate, which resulted in a civil war between Julius Caesar