The Embassy allows you to join and create Alliances, view your Alliance Diplomatic Relationships and to house allied troops sent to help you. Your Embassy must be level 2 to create an Alliance. A higher level Embassy will allow more troops to be garrisoned. An Embassy is very important in a war. Reinforcements to a city are absolutely vital in keeping yours or anyone else's city upright. make sure to have enough food to hold troops though alot of newbies do not realise they have to feed the troops that are proctecting them also.