The book is intended to present a full documentation of the Old Uigur texts of the Church of the East known from several places of Central Asia, mainly Bulayık and Kurutka in the Turfan oasis, as well as Xaraxoto.

Our knowledge about the Christian communities in the Turfan oasis is very limited. Although there are some traces of an interrelationship between the Syriac, Iranian and Old Uigur text fragments, hardly anything can be stated in precise terms, the main reason being that we have no exact dates. The only possible period in which speakers of all these groups could communicate with each other is the tenth century, when Sogdian was still a spoken language. Most of the Old Uigur texts probably belong to the 13th or 14th centuries, while the Syriac texts necessary for the liturgy may have been used by both other groups.

The themes of the texts are very diverse. Starting with fragments of a creed (A) and the legend of the Magi (B), the survey continues with several fragments of prayers and confessional texts (C, D, E, F). A letter of petition (G) gives insight into the life of a monastery. The legend of Saint George is the topic of H, while a fragment of the apocryphal acts of Paul is given in I and J is a benediction on the occasion of a marriage. Other fragments could be identified only in a preliminary way (K to P). Q is a document with an ecumenical theme. R is a Syriac text in Uigur transcription, which has been edited by M. Dickens and the present author. Of special interest are the Uigur glosses in a Syriac liturgical manuscript now preserved in Taipei (S), which will be edited by A. Muraviev in a separate publication. The few but important texts from Xaraxoto (T to W) are also included here, amongst them a sermon of five folios in which some Syriac texts, e.g. Matt. 10:42, are quoted.

The texts have been presented in transliteration and/or transcription and in German translation. Several indexes will hopefully be useful to the researcher. Special attention has been paid to the personal names of Christian origin. Material collected from many other Old Uigur texts leads to the conclusion that people who, judging from their names, were Christians interacted in business affairs with people of Buddhist background. Splitting the index of words into one for the Turfan group (A to S) and one for the Xaraxoto group (T to W) was intended to give a better opportunity for further study of the slight linguistic differences between the two groups.