The church district developed during the century of the Reformation. It was also called Lower Danubian Church District, because it embraced the congregations along the downstream part of the Danube (it differs from the Upper Danubian Church District, which later dissolved into the Transdanubian Church District). It was referred to as Upper Baranya, Ráckeve, Pataj or Pest Church District, depending on the episcopal seat. Its history dates back to 1563, when István Szegedi Kis, Bishop of Baranya moved to Ráckeve and expanded his pastoral care to the parts nearby. After the 1608 separation of the Baranya District, the Danubian Church District had five dioceses (tractus): Tolna, Vértesalja, Pest, Kecskemét and Solt. From 1629 the Outer Somogy Diocese separated from the Transdanubian Church District and joined the Danubian Church District; also, from 1714 the Lower and Upper Baranya Dioceses belonged here again. It meant a significant territorial change when in 1920 the major part of the Lower Baranya-Bács-Slavonia Diocese was annexed to Yugoslavia. Meanwhile with the formation of the Budapest Diocese in 1932 and the Pestkörnyéki (Outer Budapest) Diocese in 1938, the number of the dioceses increased to nine. (These dioceses were replaced by the North Pest and the South Pest Dioceses in 1955.) The 1952 General Convent rearranged the borders of the church districts and dioceses, thus the major part of the Outer Somogy Diocese was incorporated into the Transdanubian Church District and the Hatvan and Gyöngyös districts became parts of the North Pest Diocese.
At first the archives of the church district were managed by the bishops themselves; that was the case until the first half of the 19th century, although then some records were already collected by the chief notary. The series of the church district protocols (Protocollum Simandinum) have survived since 1626. By the end of the 18th century the synodical resolutions and other important matters were registered by the bishops themselves. Other church district documents scarcely survived from this period, which can be explained by the changes of the episcopal seat and the war conditions. The administrative records have survived since the 1790s, the diocesan protocols since the second half of the 18th century.
At the time of the 1838 flood the archives were transferred from the house of the Pest Diocese on Kálvin square and secured in Kecskemét. The church district records got mixed during their transfer, so in the following year their re-arrangement started. 21 groups were formed according to subject matters (with alphabetical marking): educational affairs, representations, diocesan affairs, etc. and then an elenchus was made at items level. The records from the 1840–1849 period were added to the elenchus that had been prepared in 1839 but the records were re-arranged a bit, so a new elenchus was made until the letter Q (Regestrum by Pethő). Later the records from 1850–1859 were arranged in a similar way but the records from the period between 1860 and 1884 were only arranged every year in three groups according to subject matter. Since 1884 the records have been registered and indexed.
The archives became a public research centre at the beginning of the 20th century. It was opened to the researchers in 1913 in the Ráday street building of the Budapest Theological Academy. István Hamar, Professor of Theology devoted great care to the library and the archives. The archives became a real scientific workshop between 1951 and 1957, thanks to the archivist work of Kálmán Benda. In 1955 the archives and the library became parts of the Ráday Collection and as a result the archival material of the Ráday Library (about 150 running metres) were taken in by the archives, including the archives of the Ráday family and the records of the Protestant agents (Archivum agentiale). The archives kept its independence within the Ráday Collection; from 1970 as special archives and from 1995 as private archives open to the public. In the meantime, from 1960 the archival material increased considerably, due to the collection of the records of the different organizations belonging to the church district. In addition to the traditional archival aids, since the 1990s digital archival aids have been prepared, processing several tens of thousands of data series.
