Nearing retirement, your seniority (in age and rank) has afforded you your pick of assignments. Fittingly, you've chosen to build your next settlement in Milagro. The island has been known to you for quite some time now. You've heard of its calming waters, but it's the abundance of natural springs there which has piqued your interest. These hot springs are known to have rejuvenating qualities, and since getting on in years, you've been wanting for ways to soothe your tired and weary muscles.
Currently, there are two factions claiming rights to the island. A small native clan, who consider the lands ancestral, has been clashing with a barbarian tribe trying to stake out a territorial claim there. Seeing a third party get involved will certainly rile them up; but as their numbers are now reduced, so will be their level of threat.
Just keep fending off their persistent attacks and an opportune time will come for you to bring home a triumphal arch. Its presence should be enough to further weaken their resolve and cease their incursions into the island once and for all.
An addendum to your mission:
Events happening offshore may have some ripple effects on your city; namely a sudden drought which has affected food production in a few provinces, and a recent upsurge in construction which has had everybody scrambling to acquire marble from all available sources.