I think that latin is the most important factor in the roman legacy because.... Latin remains extremely influential today. It is used in many languages now including Italian, Spanish, and French. The English language uses the latin alphabet plus three letters that were added in the medieval times those were J, U, and W. We also use some of the same months that the Romans used such as August, September, March, October, November, and December. Latin is also a very important factor in our law, medicine, and religion, as well. For those reasons, I think that latin is the most important factor in the roman legacy.