After its heyday in the first half of the 17th century, historical research took off again in the later 18th century, first in the form of encyclopedic summaries, then on the basis of fresh research interest, specifically focused on legal history. Monarchist-republican tensions had deepened after 1740, and some debates on the origins of sovereign power harked back to the Middle Ages. In this climate, the jurisprudential association Pro Excolendo Iure Patrio was founded in 1761 in Groningen, with an interest in ancient and medieval Frisian law. It was to play a significant role in the edition of Old Frisian legal manuscripts.

Universities also began to produce historical legal publications. The Opstalsboom, near Aurich in East Friesland, became a symbol of ancient Frisian democracy and popular sovereignty; this tree had been a gathering place for Frisians from all seven Frisian states during the 14th century. In Coert Lambertus van Beijma’s dissertation Tractatus de Grietmannis (1780) – for which the author, owing to his espousal of Patriot politics, was unable to find professorial sponsorship – the Frisian rural governors of his time were represented as the successors of the tribally-elected medieval Scheltas and Asegas. Such notions of tribal egalitarianism (ultimately derived from Tacitus and typical of Enlightenment Patriotism) resurfaced after 1815. Although the argument was embroiled in party antagonism, in 1835 two of Van Beijma’s grandsons completed their doctoral research under the supervision of the Liberal leader Thorbecke, then a professor in Leiden. Notions of ancient Frisian tribal democracy were picked up by Thorbecke and by his pupil Laurent Philippe Charles van den Bergh, state archivist.

In the meantime, the history of the people-at-large grew in popularity. In 1808, Jan Willem de Crane, professor at Franeker, proposed the idea of writing regional studies covering the entire country. This proposal coincided with the overall effort of the Bonaparte monarchy to cultivate a national spirit. For similar reasons, more popular histories were drawn from annalistic material. The Fries Genootschap, founded in 1827, played a significant role in this. Hobbe Baerdt van Sminia’s popular Geschiedenis van de onlusten tusschen de Schieringers en Vetkoopers in Vriesland (“History of the strife between the Schieringer and Vetkoper factions in Friesland”) appeared in 1829 and inspired narrative and poetic treatments of the topic. Popular magazines such as the Friesche volksalmanak or the Friesch jierboeckjen and the more elitist De vrije Fries had no shortage of historical contributions, most of which were of doubtful scholarly value. The greatest achievement was undoubtedly the genealogy of the Frisian nobility, Stamboek van den Frieschen adel (1846), by Arent van Halmael and Montanus de Haan Hettema.

While the ideology of ancient Frisian roots remained popular among a general readership, history-writing took a more factualist turn after 1850, both among amateurs and academics. Legal dissertations no longer focused on the Middle Ages, but were archive-based institutional studies on topics like dyke law (Jan Minnema Buma, Bijdrage tot de geschiedenis van het dijkregt in Friesland, 1853), the estates of Friesland (Petrus Wierdsma Schik, De Staten van Friesland voor 1795, 1857), the country town (A.A.F. van Panhuijs, De landgemeente in Friesland, 1869), and the Frisian Central Court (Jacob Sickenga, Het hof van Friesland, 1869). Wopke Eekhoff, archivist of the city of Leeuwarden, published an authoritative history of that city in 1846 (Geschiedkundige beschrijving van Leeuwarden). Eekhoff, who compiled large collections of archive material and prints for the city library, was also responsible for the development of the collection of the Fries Genootschap. His activities made it possible for the Genootschap to undertake the history of Franeker University, which in turn inspired Frieslands Hoogeschool (“Friesland’s Academy”, 1878 onwards) by Willem Boele Sophius Boeles. Boeles’s classmate Isaac Telting published, in 19 instalments, an outline of Old-Frisian private law in the legal magazine Themis between 1867 and 1882. A third acquaintance, the provincial archivist Eelco Verwijs (also a member of the Genootschap), wrote a number of important studies on the relationship between the church of Leeuwarden and the Abbey of Corvey, and about the wars between Albrecht of Bavaria and the Frisians (1864; 1869). In the years around 1860, all three were engaged in the “young Friesland association”, a study group of young legal professionals who sought to bring a more scientific spirit to the Genootschap and mocked the self-taught Eekhoff. The counterfeit Oera Linda boek (1872) was published anonymously from this circle of acquaintances; the work is often attributed to Verwijs, who possibly cooperated with his friend François Haverschmidt. This pastiche of a purported tribal chronicle, replete with mythological references to primordial Friesland and its language, in some cases sampled from, or lampooned, mythical representations advanced by Joast Hiddes Halbertsma and in publications like It aade Friesche terp. Jan Bolhuis van Zeeburgh undertook a less jocular, scholarly source criticism in his Kritiek der Friesche geschiedschrijving of 1870.