The Czechs built a wooden fortress where the residential area Hradcany stands today, and the Zlícani built theirs upstream at what is now Vysehrad. They had barely dug in when nomadic Avars thundered in, to rule until the Frankish trader Samo united the Slav tribes and drove the Avars out. Samo held on for 35 years before the Slavs reverted to squabbling. In the 9th century Prague was part of the short-lived Great Moravian Empire. Under its second ruler, Rastislav (r 846-70), emissaries were invited to come from Constantinople, and Christianity took root in the region. The Moravians (the ancient lands of Moravia now form 7 the eastern part of the Czech Republic) were ultimately undone by internal conflicts, especially with the Czechs, who finally broke away from the empire. Prague Castle (Prazsk hrad, or just hrad to the Czechs) was built in the 870s by Prince
other leg of the circuit, since they could not understand it. The military took the query as proof that Japan was monitoring the mainland communications. It was the A-3 that brought news of World War II to President Roosevelt, who was awakened early on the morning of September 1, 1939, by a call from the American ambassador in Paris, William C. Bullitt. As the United States was drawn closer and closer to war, the President conferred with his emissaries abroad more and more by scrambler radiotelephone. During the Battle of France he sometimes spoke with Bullittt several times a day. Characteristically, Roosevelt liked the telephone because it cut through the red tape of diplomatic routine and the delays of coding and cabling and because it gave him personal contact with the speaker. Occasionally he spoke' with Premier Paul Reynaud, and frequently and increasingly with Churchill.