The Battle for Fort Greenwall

Background
"Legate Rikke/Galmar Stone-Fist has sent me to assist in taking Fort Greenwall from the enemy."

Walkthrough
This quest can happen in both Imperial Legion- or Stormcloaks-questlines depending on whether the Dragonborn agreed to hand over Riften to the Imperial Legion during the quest Season Unending or not.

If Riften is still under Stormcloak-control talk to Legate Rikke at the Rift Imperial camp.

The quest giver will give you an assignment to assist the allied soldiers at Fort Greenwall. Travel to Fort Greenwall which is located north of Riften. Follow the trail and you'll eventually see it. Once you meet up with the soldiers they will automatically charge at the Fort. Attack the Fort with your fellow soldiers. It's best to take out the barricade and kill the archers near the main wall of the fort. Once you have reached the remaining enemies are 0% the quest will be complete.

Tips

 * There is a way to finish this quest without going to Fort Greenwall simply go to Mistveil Keep and hit Jarl Laila Law-Giver until she fell on her knees and the quest is finished.
 * Taking out the archers in the beginning is recommended before destroying the barricades.
 * It is best not to attack where the enemies spawn because you can easily be overpowered.
 * After you kill one of the enemies, take their items. When you become over encumbered, drop the surplus items. Otherwise, you won't be able to recover the items later, as many of the soldiers disappear after a certain amount of time.
 * Also if a Dragon spawns near the meet up point, get its attention and run to the fort. It will take out most of the soldiers until it decides to attack you. You will lose men but they will continue to respawn.
 * If you have completed the main quest or have the "Call Dragon" shout, summon Odahviing to help you attack the fort, the dragon will only attack the enemy (whichever side you're fighting) and can make the battle significantly easier and a lot more epic.

Bugs

 * Sometimes, no one will spawn at this battle and you won't be able to complete it normally.
 * Solution: Open the console and type "setstage CWFortSiegeFort﻿ 9000". The "Regain The Rift" objective of the Reunification of Skyrim quest will be completed automatically.
 * Solution: Go to Mistveil Keep in Riften and sneak into the Jarl's Quarters. Wait until she goes to sleep then go up to her and sneak attack her. It will suddenly say that the Battle for Fort Greenwall is complete and so is regaining the Rift. You will report to General Tullius and that will be the end of this part. (no achievement is awarded)
 * Solution: Clear the waypoint arrows (having none selected) before being assigned the quest.
 * Solution: Use the wait feature excessively such that the likelihood of Stormcloaks appearing increases.
 * If having taken the Rift in "Season Unending", Legate Rikke is still trying to send the Dragonborn to Fort Sungard instead of Fort Greenwall (without a quest marker appearing on the map).
 * Solution: Sneaking into Understone Keep and killing the new Jarl should complete the Regain The Reach objective and The Battle for Fort Sungard.
 * Sometimes, the promotion to Tribune may not occur.

Битва за форт Гринвол Die Schlacht um Festung Grünwall