The Moravian Church had been looking for somewhere in Denmark to build. On 10 December 1771, Christian VII gave them a royal concession that was close to irresistible: ten years free of taxes, ten per cent of the construction cost of every new house paid from the crown, freedom to trade, freedom from the guilds, exemption from military service, and the right to run their own religious affairs without interference. In 1773 the Brethren began building on open farmland in Southern Jutland and named the place for the king who had made it possible. It was a colony of a religious movement whose mother settlement, Herrnhut, lay in Saxony, and the new town's plan borrowed directly from earlier Moravian foundations at Herrnhaag and Gnadau.

Most Danish towns accumulated. Christiansfeld was drawn first and then constructed, and the bulk of it went up between 1773 and 1800. Two parallel streets run east to west on either side of a central Church Square. The church hall stands on the square with the Sisters' House, the fire-house, the vicarage and the provost's house; the shops, the Brothers' House, the hotel, the school and the ordinary dwellings line the streets. The buildings are one and two storeys, yellow brick under red tile, repeated with almost no variation — the same architectural argument the cemetery makes, in a different material. The population reached 279 by 1779 and roughly 400 by 1782, which was about the size the plan had anticipated.

Moravian communities organised themselves into what they called choirs — groupings by sex and marital status, each with its own devotional life. At Christiansfeld the unmarried and the widowed lived communally in three great houses: Søstrehuset for the sisters, Brødrehuset for the brothers, Enkehuset for the widows. From these buildings members walked to their own doors of the church hall and sat in their own sections during worship, men on one side, women on the other. The hall itself is plain to the point of severity: whitewashed, flooded with daylight, without altar theatrics or ornament. To modern eyes the arrangement can look confining. To the people who chose it, it was a way of belonging to something whose rules applied to everyone equally — which was more than most eighteenth-century arrangements offered anybody.

The town is famous, throughout Denmark and well beyond, for its honningkager. The recipe dates from 1783 and is still secret. Until 2008 the cakes were baked in the original eighteenth-century bakery; new national sanitary standards forced a renovation, but the recipes did not change. It is a small thing beside the theology, and it is the reason a great many Danes visit at all — which the Brethren, who were pragmatic people running a working town with a working economy, would probably have found perfectly reasonable.

Christiansfeld lost its administrative standing in the municipal reform of 2007, when the municipality it had led since 1970 was folded into Kolding. What it had instead was an intact eighteenth-century town. Denmark put it on the UNESCO tentative list in 1993; it was inscribed on the World Heritage List on 4 July 2015 as the best-preserved example of Moravian town planning and architecture anywhere. Serious money followed the recognition, and some of it came first: in 2009 Kolding Municipality and the Realdania foundation committed 100 million kroner to restoring the historic core, and in 2012 the A.P. Møller og Hustru Chastine Mc-Kinney Møllers Fond gave 60 million kroner to the Sisters' House alone. Roughly 3,100 people live here. The church square, the two straight streets and the field of identical stones look very much as their builders intended, which was the entire point.