The Swedish Viking Age lasted roughly from the 8th century to the 11th century. It is believed that Swedish Vikings and Gutar mainly travelled east and south, going to Finland, Estonia, the Baltic countries, Russia, Belarus, Ukraine, the Black Sea and even as far as Baghdad. Their routes passed through the Dnieper south to Constantinople, on which they carried out numerous raids. The Byzantine Emperor Theophilos noticed their great skills in war, and invited them to serve as his personal bodyguard, known as the Varangian Guard. The Swedish Vikings, called Rus are believed to be the founding fathers of Kievan Rus'. The Arab traveller Ibn Fadlan described these Vikings as follows: