He declared Aten to be the god of Egypt. Ramose changed his name to Mose, since "Ra" was the pagan name for the sun-god, which had been outlawed.
During this period, "advances" in the handling of livestock involved keeping pigs and ducks in closer proximity. Unfortunately, this breeds the bacteria that cause influenza, and the country was swept with flu epidemics. The less superstitious Atenists figured out that it had something to do with pigs, and simply eliminated pork from their diet.
1,2:5 This practice persists in Jewish dietary law (i.e., the Kashrut). The Talmud went on to prohibit cooking meat and fish together or serving them on the same plates, because it is considered to be unhealthy, and the Shulchan Aruch explicitly states that this could cause and/or exacerbate the plague,
3 even if we now know that the more direct correlation is between pigs and waterfowl. The more superstitious among the Egyptians considered the epidemics to be signs that the gods were not pleased with the Atenist regime. The Amun priesthood worked hard to kindle this into a loss of confidence in Akhenaten.
The Egyptian version of the story maintains that the inhabitants of Amarna were already diseased,
4:b1:§26 but we don't know if this is to be taken literally or figuratively.