Lushina Maria G. RussiaSaratovSaratov State University, 83 Astrakhanskaya St., Saratov 410012, Russiamaria_lushina@mail.ru Author's articles Гнезно и Познань: спор о первой столице Польши Cities of Greater Poland from the Middle of the XI Century to the Middle of the XII Century Gniezno and Poznan in the XIII Century