Thank you Angelina:
I will look at Wikipedia to find out about Guatemalan history.
Or perhaps I will go to the Public Library in zona 1, I love to browse old history books!
But I still insist that Xela was founded first, if you look close to the conquistadores´journey, I think they got to Xela by the south coast side (Reu) they hiked the mountains and made a stop at the "Llano del Pinal" which is a big flat land at the slopes of the Santa María volcano, then they came to Xela then they headed to Salcajá and so on.
It´s just a probability.