...somewhere on the front lines as a volunteer. He's gone from his spot in Ishgard and talking to Emmanellain and Honoroit in Dragonhead gets this text:

Emmanellain: "Ameme! I thought you would be with the others defending the border at Ala Mhigo. I intended to volunteer my services, but alas, my dear brother was a few steps faster. With him gone, it falls to me to keep watch over House Fortemps."

Honoroit: "Worry not about Lord Emmanellain. He appeared devastated at the news that he could not venture to Ala Mhigo, that much is true. But deep down, I believe he is quite relieved that he can stay here at the manor."

A lot of things can happen in a war and I'm seriously amazed that Edmont would let the newly minted count just run off to fight a war in another country.