Svend I de Dinamarca
According to other researchers Estrid was the daughter of Sweyn Forkbeard and Sigrid the Haughty, herself the daughter of Skagul Toste, making Olof Skötkonung, the son of Sigrid the Haughty and Eric the Victorious, Estrid's half-brother while Canute the Great, Harald and Świętosława her other half-siblings, as children of Sweyn Forkbeard and the Polish princess Gunhild, daughter of Mieszko I of Poland.