In what order should I level research at the start of a Reign?

Since everything resets each Reign, you re-grind this order every season. The recommended order:

1. Base Infrastructure (production + Storehouse) — without resources, nothing moves.
2. Army Expansion + Dragon's Army — more slots and more capacity = more waves, the sinew of war.
3. All-breeds stats (First Flame plus your dominant breed's stat) — profitable because they're global.
4. Relentless Assault + Stalwart Defense — global PvE multipliers.
5. Damage/Defense for YOUR troop type + Siege Precision if you take seats.
6. Breed-targeted Dragon Care plus logistics (Swift Stride) to finish.

➡️ And hold the line: Stronghold Tier 10 before the Reign ends for the campaign loot.