Although Dietrich is an eyewitness for much of what he describes in the
Libellus, he also makes use of other eyewitness reports and of written sources to round out his account. He used as a source the same compendium as used by John of Würzburg. In his introduction, he gives his work a spiritual purpose: to help bring Christ to mind for those who cannot see the Holy Places themselves and thereby to love and pity him, bringing themselves closer to heaven. Dietrich's pilgrimage can be dated to between 1171 and 1173, during the reign of King
Amalric of Jerusalem, when the Holy Places were under Christian control. It began in
Acre during March or April. From there he took the road to
Jerusalem,
Jericho and the
river Jordan. He went back by the same route and was in Acre preparing to embark on the Wednesday of
Easter Week. He may have made a detour to visit
Nazareth,
Tiberias and
Mount Tabor, but his description of the
Sea of Galilee is very confused. His description of the
Church of the Holy Sepulchre indicates that he was there during the renovations financed by the Emperor
Manuel I Komnenos. He is also the earliest source to mention the
Sultan's Pool, then a newly constructed cistern. The skill and detail of Dietrich's architectural descriptions has led to the suggestion that he was an ecclesiastical architect. He clearly had knowledge of construction techniques and building materials, and his descriptions are clear. The
Libellus is an important source for the art, architecture and agriculture of the
Kingdom of Jerusalem on the eve of its fall. Dietrich shows less interest in miracles and wonders, but does provide a first-hand account of the coming of the
Holy Fire. Although "he directs no sarcasm against men of other faiths", he does show
anti-Jewish prejudice and records being frightened by some local "
Saracens" shouting in
Arabic as they worked in a field. ==Manuscripts==