The Battle of Midvale was a major engagement that took place in the early years of the Human-Covenant War over the Outer Colony world of Midvale. Midvale was an important agricultural colony that was the breadbasket of the whole sector. Battle Group Echo composed of forty-four ships under the command of Rear Admiral Sebastian T. Shelby was stationed at Midvale to reinforce its defensive fleet and protect it from any alien attack. CENTCOM believed that this would be sufficient to deter an attack.