July is Julius Caesar's Month
It’s July in English, Juliol in Catalan and Julio in Spanish. In Latin it was Iulius. But before being Iulius it was Quintilis, meaning the fifth month of the year, in the same vein as September (the 7th month), October (the eighth month), November (the ninth month) and December (the 10th and last month). The original Roman calendar had ten months.
Under the reign and probably the political coercion of Augustus Caesar and Marc Antony, one year after the assassination of Julius Caesar, in 45 BC the Roman Senate changed Quintilis to Iulius during the reform of the Julian calendar, to honor Julius Caesar and his month of birth.
It’s likely that political coercion on the part of both Augustus was necessary because at that time the Senate was still composed of the men who had stabbed him to death on the Senate floor. Marc Antony was credited with proposing the idea and it's likely Augustus who pushed it through the Roman Senate.
In Anglo-Saxon England July was known as Æfteraliða (after-litha) before being replaced by the Julian calendar sometime between 725 AD and 1066 AD.