The celebration of the Millennium of the Baptism of Poland was undoubtedly one of the greatest events in the country, not only because of the political character given to it by the communist authorities, but above all because of its religious and moral significance. The harsh attitude of the authorities and the long period of preparation before the main celebrations in 1966 played a significant role, leading to a series of measures against the Catholic Church.
Although the main celebrations in the Bialystok voivodship took place in the second half of 1966, information about the preparations was already gathered at the beginning of the year. On 1 March 1966, Colonel Leon Sobczyk, Deputy Provincial Commander of the Citizen's Militia for Security in Bialystok, informed Captain Edward Rodziewicz, Head of the Independent Organisation Section at the Provincial Headquarters of the Citizen's Militia, that the programme for the celebration of the Millennium of the Baptism of Poland in Drohiczyn had been prepared on the basis of the guidelines contained in the national programme. He pointed out, among other things, that the Jubilee will have a primarily Marian, ecclesial, national and pastoral character. However, according to the SB in Łomża, the first town in the voivodeship to be visited by the bishops' representatives, the local clergy had already begun to organise the Jubilee celebrations in stages after the official talks on the manifesto had ended. Forty-two bishops and 107 priests from the diocese came to the city with Cardinal Stefan Wyszyński as part of the millennium pilgrimage on 6 and 7 August 1966. Of all the sermons, those of Cardinal Wyszynski and Archbishop Kominek were the most criticised. In Lomza and Drohiczyn (1-2 October 1966) various events and rallies were organised to keep the youth and the public away from the celebrations. The Security Service was very active in these towns, using its network of spies.
The examples of Lomza and Drohiczyn allow us to assess the attitude of the state authorities towards these celebrations and their efforts to play down their significance. Although many of the activities described in the article were carried out by the security apparatus and the administration throughout the country, specific situations arose in this region. One was related to the fact that three dioceses were involved, with clergy and faithful against whom a series of repressions were organised. Another interesting phenomenon was the attitude of the Orthodox population living in the eastern part of the province towards the organisation and conduct of the millennium celebrations. This issue was important in that the celebrations were perceived by some of the sect's clergy as a threat to the Orthodox Church.