ORIGINAL: Murat
You should have lost both. A garrison does not let you conquer a minor controlled by a major that is neutral to you, you need to keep a CORPS there for a complete month (a corps needed to be sitting in each area at the END of May if you went in in April). Garrisons only conquer areas controlled by nations you are at war with.
This is not technically correct. Actually, any factors can cause the change of control. But, if one does not have a corps counter in the nation during a diplomacy phase, there is a lapse of war.
This came up several weeks ago, when people noticed they were losing minors after they left them. It usually turns out that it was the other guy foraging that opened the city up, not combat.
There are two scenarios in question (these assume Prussia at war with X, with no other major powers involved in any way):
First, Prussia besieges the city in April, breaks in, and wins. This actual breakin occurs at the end of the land phase (land combat, to be specific), so no further movement is possible (other than in and out of the city).
If Prussia leaves the country, but leaves a factor in the capital, Prussia will gain control at the end of May. Prussia does not have a lapse of war, because lapses only occur during the diplo phase. Only the May diplo phase is in question, and Prussia had a corps in the nation during May's diplo phase. Actual change of control occurs after the land phase (in May, in this example).
Second example: Same situation, except Prussia fails to break in April. If for any reason, Prussia leaves X during May, such that no corps counter is in the nation, war will lapse regardless of whether Prussia left a factor in the capital or not. Now, you say, how could Prussia leave a factor, when he didn't win the combat. The answer is foraging. If the garrison died, then it would APPEAR to Prussia that he had control for the whole month. In fact, he would not have, because he would not have controlled it between his movement and the controller of X's movement. This trips up everybody I've talked to once or twice.
In the second example, the month of conquest is shifted to June, not May (due to not having control for ALL of the month).
By the way, there are other end-cases as well, but they are more straightforward. For example, if Prussia leaves the capital garrisoned, but move the corps to another area in the same minor nation.
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