History of All Battleground Missions

All Battleground Missions is a Season of the Chosen triumph (25 points per wiki data; one guide lists 15) required for the Chosen seal. Complete each Battleground activity at least once.

How to complete

1. Finish one run of every Battleground. Completions can come from the Battlegrounds playlist or from the individual mission.
2. TheGamer lists the four as Behemoth (Nessus, boss outside a Cabal tank fortress), Hailstone (Europa), Foothold (Cosmodrome) and Oracle (Nessus, underground Psion boss).
3. The playlist rotates, so queue it repeatedly until all four are checked off. Only one completion per Battleground is needed.

Notes

Sources disagree: Shacknews names the four as Behemoth, Hailstone, Cleansing and Oracle, TheGamer has Foothold instead of Cleansing. Check the triumph's in-game progress to see which are outstanding.