You decide not to call for mobilization and send the Marshal to do the fighting.
858 AD, Spring
You receive a report that your Army have won a skirmish against vanguard of the Parsians and have clashed with part of their invading army at Paennach Fields, winning this battle as well.
858 AD, Mid-Spring
You receive a report that your Army fought with the main body of the Parsian army and routed it without causing much damage at the Battle of Óin Bridge.
A week later comes a report in which the Marshal describes several skirmishes with Parsians, who have taken some well-defended positions in the more hilly parts of northeastern Luathbas.
858 AD, Late Spring
First you receive a report about Battle of Coen Hill in which your Army was routed by a column of Parsian Cataphracts that smashed into your men and sent them running.
Then you receive a report about a detached part of your Army recapturing few strategic border outposts.
The third report of this time is about Second Battle of Coen Hill, where your Army beaten a large unit of Parsian infantry, as their Cataphracts were elsewhere.
858 AD, Summer
Another battle report comes in: a small unit of your Army that tried to cut the Parsian supply line was soundly defeated by Parsian Cataphracts in Battle of Fieorach Valley, which leads into the mountains separating Luathbas and Parsia.
The priests of the God of the Hunt have arrived at your castle to speak with you.
"Our beloved king, we have studied the signs given to us by the spirits of the forest and it seems that now would be the year of the anniversary of the Hunt of the White Stag! It happens once per a generation of men at best, and it is a glorious tradition, so we hope that you will accompany other nobles and our hunter-priests to seek and kill the White Stag, which burnt on altar could bring peace and prosperity for Luathbas for the coming years! All we need is some donations from the Treasury to host the event, sire..."
A) Bleh! A hunting trip is best moment to get you assassinated! No hunts with you in them, nope!
B) It could do nicely to help you stretch your legs now that you're not actively leading your men in bloody combat!