DairthechIn Gaelic Ireland, between the 5th and 9th centuries AD, a dairthech was a type of oratory or church built of oak-wood.HistoriesThe dairthech was the earliest kind of church built in Ireland, from the earliest Christian times onward. They were gradually replaced by stone churches.StructureA typical dairthech was rectangular, measuring by. Some were wider up to, and congregations of 150–260 people are recorded. It had a high pointed gable. Oak was used as a building material as a holdover from Celtic religion, where the oak was imbued with magical powers.Internal structureLittle is known about the internal structure of the dairthech, although descriptions of the murder of Echtigern in Kildare in AD 760 offer a few hints, mentioning a chancel-screen and altar. Cogitosus describes painted partitions dividing clergy from laity and women from men.