The genitive case is used in several situations (for more readhere), and one of them is to indicate a starting point after the preposition “from”.
Examples 1. Это Берлин. Я из Берлина. - This is Berlin. I'm from Berlin. 2. Это Москва. Он из Москвы. - This is Moscow. He is from Moscow. 3. Это Монако. Они из Монако - This is Monaco. They are from Monaco.