They aren't quite the same. I think you're right that they would be said in the same situation. But there's a different implication with 'even'. The suggestion with both is that he was distracted or oblivious, or something similar. But with 'even' - you are emphasising the fact that he was _so_ unaware, that he would not notice such an obvious and momentous thing as the result of the death of a monarch.

You would use these sentences only if you're referring to a hypothetical situation. In other words, if you want to talk about something that could happen even if it hasn't happened yet. In this case, the possibility that the king died and the city would mourn for him exists. However if this was to happen, Jamie would never know due to whatever circumstances he's currently in. I hope this helps. [emoji]

I think #1 and #2 are the same, they can be said in the following context, for example: Jaime was so distracted that day that he didn't pay attention to whatever happened in the city.