The times of rule of John Casimir (1648–1668) put the people of the Polish–Lithuanian Commonwealth, its political nation, elites and state institutions, in the face of new, unknown so far (at least not to such extent) challenges and difficulties. The most severe were wars that along with the Rebellion of Bohdan Chmielnicki and then the Deluge entered far into the territory of the Commonwealth, reaching lands which for decades had enjoyed peace. The subsequent war campaigns not only brought about territorial losses but also upset socio–economic state foundations. They also came as a great psychological shock to people and produced damaging effects in the sphere of widely understood social consciousness. A serious problem was caused by heightening of internal tension in which one party was the Court and king and which led to a grave crisis and finally to a civil war. It was accompanied by growing inefficiency of the Sejm. – a Sejm floor became an arena for current political fight which engaged even a parliamentary procedure. All these factors consistently led to a change of position of the most important institution of the noble democracy. The Polish-Lithuanian parliament was systematically losing its legislative and decisive significance (a symptom of which was dissolutions of consecutive sessions without any resolutions and victory of the Liberum Veto principle), becoming a strictly political body. Another vital element of the crisis of ruling system was a collapse of the relations between the king and the political nation. This fact, which is not questioned by historians, had a very complex origins. The king himself missed his chances to come to agreement with the political nation, pursuing mainly a policy of agreements or fight with individual magnate factions over the heads of the noble public. In general, relations between the ruling and the subjects in the historiography were depicted from a perspective of the ‘centre’. In my work I tried to look on the problem in different dimension and from another, issuing from the rank and file, perspective. To begin with, I would like to explain that, unlike many authors, under the term of ‘centre’, ‘central rule’ I understand not only the king and the court but also the Sejm Walny (General). In the then political reality of the Commonwealth, where the policy of the king was restricted by acceptance of the Sejm, the Sejm performed a key role, not only political but also in social consciousness. Local community was a ‘communitas terme’ – land community of specific dietine. The most frequently I used this term in its narrow sense – a community of the local nobility. A state of the source materials does not allow to depict in satisfactory way the actions of other estates. I put into the background the questions of big politics (although they never fade completely). The work focuses on several plots. First of all, I am interested in opportunity of local communities for passing over their opinions and problems, in a word, in the ways of communication with the centre which were open for local communities in such difficult times of almost permanent external threat and internal crisis. To which extent the new challenges and difficulties were modifying existing working mechanisms and what was direction of an evolution? Taking up this theme we are entering a subject of widely understood social communication in the modern times. Due to deficiency of the source materials we cannot apply in full form a notional and methodological apparatus used in contemporary theories of communication by scholars of other disciplines: sociology, social psychology, political science, economics or management. Therefore I made use of selected elements present in any process of communication, both individual and collective. I focused my attention on participants of communication processes (recipients and senders of particular message, regardless of its importance), the problems of functioning of the communication channels and return message. In historical reality described in the text the (collective) sender was a local community, and collective recipient was the Sejm; quite often there was a distinct individual recipient – the king. On the local level a function of the transfer channel was performed by the dietine, while on the higher stage, the channel between the local and central level was formed by the envoys and regional senators. In the next chapters I described the way in which these separate links were functioning in actual situations and realities of John Casimir’s times. The mechanisms formed in the 15th and 16th centuries, based on idiosyncratic communication chain: local communities – dietines – envoys and senators – centre (Sejm and king), were still quite efficient in the first decades of the 17th century. The crisis of the centre visible in the times of John Casimir forces us to analyse the changing role and situations of the other elements. Reactions of local communities to the current needs and difficulties were fairly flexible. Immediate threat stimulated them to better organize themselves which was reflected in much increased number of diverse assembles of the nobility. There was little attention paid to formal divisions of individual dietines. First and foremost care was taken to secure legality for the assembly. And every dietine after having accomplished its purpose (sometimes only in part) considered all matters that currently needed to be decided on. In the face of less and less efficient Sejm the dietines were taking over some of its authority, which, on the one hand, showed the adaptation abilities of local communities and dietines, on the other hand contributed to the weakness of this most important institution of the Commonwealth. In the whole system an important role was played by information circulation that on local level was performed in two ways: official and unofficial. An access to information depended on individual opportunities of each member of the community. The key role in the communication between the locality and centre was played by the envoys and that is why importance was attached to their election and ‘quality’, that is personal virtues. In the sphere of pledges emphasis was placed on ethical values and qualifications of the envoys. However, the practice often deviated from the ideal. Local communities were gradually losing their influence on appointment of seats in favour of growing in strength political factions. The conduct of an envoy in session depended on many factors. Although local communities attempted to restrict the leeway of their representatives obliging them (occasionally under oath) to strictly obey the instructions, in practice the envoys could treat these orders fairly flexibly. It depended mostly on actual arrangement of power in the Sejm. In the instructions much space was taken by local matters, but in quality dominated nationwide issues, concerning the condition of the state, internal and external security, financial situation of the Commonwealth and functioning of system of justice. The envoys performed a double role: a representative of the local community and participant of the decision-making processes on the central level (Sejm). Similar function was performed by the senators, although on different rules. The experiences of the two decades of John Casimir reign revealed the obstructions of institutional informative channels; the senators were not performing their informative function, an effectiveness of the envoys was decreasing. Even the biggest flexibility of the local communities and dietines (i.e. on the local level) could not help to make permeable the whole system. It frustrated the local communities and triggered the tendencies to seek direct communication with the centre with the omission of existing links. Was there a possibility of setting back or adverting the crisis of communication mechanisms of John Casimir times? The solutions were possible, at least in theory, either by strict observation of the principle of ‘mixt monarchy’ (although the subtle balance between its elements had been upset in earlier times, and short-sightedness and lack of strategic thinking of last Vasa led in the opposite direction) or by blending faction system into political structure of the Commonwealth. It would have had to be accompanied, however, by an evolution of faction, based on personal relations with a patron, into a group (party or section) which would be united by common (for longer period) political stance or programme. translated by Grażyna Waluga