What has Claudius just announce

I assume your referring to the first act?

Claudius announces that he and Gertrude have just been married. This marriage has followed quickly after the death of the former King of Denmark, Old Hamlet, Claudius’ brother. Claudius addresses the quickness of the marriage, representing himself as in mourning for a lost brother even as he is joyful for a new wife, his one-time sister. Claudius also addresses the question of the young Fortinbras’ proposed invasion. He says that he has spoken to Fortinbras’ uncle, the King of Norway, who has made Fortinbras promise to halt any plans to invade Denmark.