Of the various sources that deal with the beginnings of the Cistercian Order none was as popular as the Exordium Parvum (i.e. an epistle of the first Cistercians to all their successors). Its Latin version can be found in 35 MSS and c. 20 printed editions; there exist also numerous translations into other languages. The original letter must have been written by one of the founding fathers of the Order and its first monastery, probably St Stephen Harding. He recounts the beginnings of the new monastic community against the historical and legal backgrounds. The document is divided into eighteen chapters preceded by a Prologue and forms a orderly whole, although the Citeaux foundation story is not arranged in a strictly chronological order. A critical edition of Exordium Parvum was published recently by F. de Place. The first Cistercian monks arrived in Poland in the years c. 1140 (?) — 1153, when their order was in its heyday. Until recently the monastery at Jędrzejów had been regarded as the oldest Cistercian abbey in Poland; however, in the light of latest research that distinction should rather go to the monastery at Łękno. Although the formal procedures connected with the setting up of the Łękno and Jędrzejów monasteries were running parallel, the charters confirming their foundation bear different year dates, 1153 and 1154 respectively. Z. Kozłowska-Budkowa has shown that the dating in those documents follows the Pisan (Annunciation) style. It would mean that the Łękno charter was promulgated between 25 March 1152 and 24 March 1153, while the Jędrzejów charter was issued some time between 25 March and the middle of August 1153. These findings make it clear that the BVM and St Peter’s abbey at Łękno was the first Cistercian foundation (protoabbey) in Poland; it was followed first by Jędrzejów and then by twenty four other monastic communities of the Cistercian observance.