Diplomacy in King Arthur II is rather important, because the various diplomatic actions provide substantial bonuses and advantages. Each possible diplomatic partner has a selection of actions available. If there are no actions displayed, then diplomacy simply isn’t available with that particular power. Diplomatic actions may have prerequisites, chiefly a minimum reputation requirement. You can increase your reputation through your decisions in the storyline, and certain diplomatic actions like sending gifts. Once a diplomatic action becomes available, you can activate it any time. Note that activating an action does not mean you have to go through with it. You can still cancel the action, as long as you don’t make a choice.
Most actions are permanently displayed, but some of them only appear under certain conditions, and some even disappear after a while. Gifts are typically such actions, because they are linked to certain occasions – like someone’s birthday. For this reason, it is worth it to take a look at the diplomacy screen whenever the diplomacy icon is flashing.