As of summer 2011 the database contains complete information about dedications in the diocese of Hólar, Iceland, based on surviving collections of church charters, or máldagar. An article based on this material and providing a provisional analysis of the cult of saints in the diocese in the latter Middle Ages has been published as "Saints of Hólar" in the electronic journal Perigrinations, see pp. 7-37.
It is possible that individual references to churches and dedications have been missed; users who find such references are asked to inform Margaret Cormack at
Lands, dues, rights, and placenames have not yet been systematically entered. Locations of churches on Google Earth are approximate.

Note on Icelandic Data

The Icelandic data was the first to be entered, and the conventions described in the For Potential Contributors were in the process of development. There may thus be some inconsistencies in that data, which are being corrected as they are found. The following notes should be read in order to understanding and evaluate the Icelandic data.

1) Alphabetization and case endings
In the following, æ, ö, and Þ are found at the end of the alphabet. No distinction is made between accented and unaccented vowels (a vs. á, e vs. é, etc.) With apologies to speakers of Icelandic, all place-names have been presented in the nominative case. This makes using the database easier both for foreign users and computer programmers, and avoids problematic decisions as to which preposition may be appropriate in a given place-name.

2) Variation in nomenclature
Icelandic place-names are descriptive, and rarely unique. The Bæjatal on the webpage of the Stofnun Árna Magnússonar at gives eleven entries for farms called 'Reykir', indicating the presence of hot springs, not counting compounds like the name of the capital city, 'Reykjavík'. Furthermore, nomenclature is very fluid. Names can change with time and legitimate variants can exist at the same time. Subdivision and the resulting necessity of distinguishing two farms where one existed in the past means that three medieval farms on which half-churches stood, Torfustaðir (so indexed in DI, though the spelling corresponds to "Torfastaðir"), Reykir, and Ós in Miðfjörður (DI IV p. 513) are today represented by Efri-Torfustaðir and Neðri-Torfustaðir, Ytri-Reykir and Syðri-Reykir, Stóri-Ós and Syðsti-Ós. It is sometimes possible to determine which of two alternatives represents the main medieval farm with which the church was associated; I have accepted traditions recorded in the Jarðabók Árna Magnússonar og Páls Vídalins (JÁM), which mention the former presence of a church at Neðri-Torfustaðir and of a half-church at Stóri-ós. Reykir, however, was still a single unit, referred to by some as Stóru-Reykir; the former presence of a half-church is mentioned in JÁM.In cases like Reykir, choice of one of the two modern alternatives as the LocationName represents an educated guess, as do latitude and longitude.
The terminology used in JÁM should not be taken as definitive: most of the churches mentioned had fallen out of use by the time it was compiled, and the fact that Neðri-Torfustaðir is said to have had a "church" rather than a "half-church" should not be taken to indicate the presence of a full church there without further documentary support. Neither should references to bænhús (chapels) in post-medieval sources be taken to accurately reflect the status of such buildings, the term may simply indicate the fact that an ecclesiastical building of some sort stood on that location.
References to larger geographical districts (Fljót, Skeið, etc.) have sometimes been included in the hope that they will provide some guidance to users familiar with Icelandic geography, but no attempt has been made to regularize such references to a given time, place, or type of administrative district. Modern administrative nomenclature is at most a few decades old, and will not be found in older maps or documents. If reference is made to fjords such as "Skagafjörður" and "Eyjafjörður", the area referred to can extend inland on either side of the fjord and sometimes a considerable distance from the bottom of the fjord. If you are not familiar with Icelandic geography, Search Locations and Categories will take you to the correct location.
While the database is not designed primarily for linguists, those interested in older spellings, such as "toruastaudum" (dative case) for modern "Torfustaðir" can find the older spellings (subject to the limitations of Microsoft fonts) in the More Data section of the database.
For discussion of how names can change with time, or vary according to local patterns of use, see Cormack, Margaret, "Possible Christian Place-names in Medieval Iceland", Viking and Medieval Scandinavia 6 (2010) pp. 31-82, esp. pp. 33-34 and 37-38.

3) Types of church and chapel
Half-churches appear to be unique to Iceland: they are churches at which half the normal number of masses are sung, but are distinct from free-standing chapels. In the database they are found under the category 'church' with the type 'half-church'. Bænhús is the standard Icelandic term for a free-standing chapel, stúka for one inside a church. The term kapella first appears in Iceland in the late Middle Ages.

4) Icelandic Episcopal Registers
Most of the SourceDates derive from registers collected by Icelandic bishops. Not all such registers are complete, and not all bishops were interested in recording the same kind of material. For example, the register of Bishop Auðunn has clearly lost a leaf or more, resulting in the loss of máldagar for churches in Hörgárdalur (Laugaland, Bakki, Myrká, Öxnhóll, and Auðbrekka). Another lacuna accounts for the lack of máldagar from Kvíabekkur, Knappstaðir, and Stóra-Holt. That all the above churches were in the original register can be seen from the list of churches at its end, which also mentions churches at Flugumýri and Keta (otherwise known only from post-Reformation sources) (DI II pp. 487-89). Auðunn included only churches with resident priests, and did not always record their dedication.
As can be seen by choosing 1360-89 as a SourceDate, the máldagar collected by Bishop Jón skalli are only from the Eastern and Western parts of the diocese. The Sigurðarregister of 1525 is also incomplete, but contains the first complete inventories for the religious houses in the diocese. Furthermore, even when we have an inventory, it is not always clear whether the register is recording an up-to-date inventory from the church, made at the time of the bishop's visitation, copying an earlier register, or adding items acquired at a later date. Even such apparently precise dates as 1318 are approximate.
It thus cannot be assumed that the total number of churches, images, or dedications can be tracked simply by comparing absolute numbers found in the various sources.

The registers used and their approximate dates are those of:

Auðunn Þorbergsson, 1318 DI II pp. 423-89

Jón skalli Eiríksson, 1360-89 DI III pp. 155-78

Pétur Nikulásson,1394 and later DI III pp. 508-591

Ólafur Rögnvaldsson, 1461 and later DI V pp. 247-361

Jón Arason, the oldest part of the Sigurðarregister of 1525, DI IX pp. 293-334.

Other smaller collections have also been used.

5) Default saints
When the Icelandic data was initially entered, I was not concerned with saints not known in Iceland, and did not use the "nescius/unknown" option for identifying saints. In Iceland, unless otherwise stated, "Margaret" is Margaret of Antioch, "Mary" is the BVM, and other saints are, generally speaking, the most common Western-European saints of the name.