Goodgame Empire is a browser-based online real-time strategy game developed and published by Goodgame Studios. It is aimed at casual players who only play a few minutes per day. It originally launched in 2013. The game has been translated into more than 20 languages so far, so depending on your country, most likely there is a version of it that is in your language.
The game itself takes inspiration from other similar online RTS games, but it takes place in a medieval-style world. You start with one undeveloped village, and a small castle which has several plots to construct in. Constructing more buildings and amassing lots of resources are required to support larger armies and for faster resource gains. Everything in the game is time-gated: you give orders, and they will take a certain amount of time to complete.
Players can create or join alliances, and negotiate with each other via written messages. You have about 7 days of complete protection from attacks after registering; best advice is to use this time to look for an alliance in the beginning to help you.
The graphics are quite nice for a 2D browser-game, and it can be played on any computer with internet access, and it doesn't take much time to issue orders and check up your empire during each short session.