Famous scientists A.T. Fomenko and PN. Nosovsky, in a popular book intended for a wide range of readers, talks about his research on the chronology of ancient and medieval history, which led to the creation of a new chronology, significantly different from the generally accepted version of Scaliger-Petavius. The book criticizes the traditional version of the history of Rus', China, England and a new version of the history of these countries is proposed, consistent both with the new chronology and with the numerous evidence of old documents. A general scheme of the tentative reconstruction of history from the 10th to the 17th centuries AD is given. The calendar and astronomical basis of the dating of the Nativity of Christ and the First Ecumenical Council in Nicaea, accepted today, is analyzed. The fallacy of both of these datings is shown and new, corrected dates are given: 1095 AD. for the crucifixion of Christ and the era of the VIII-XIII centuries AD. for the Council of Nicaea.