In the absence of written sources from the Middle Ages, such as the Norse Eddas or epics, Latvian mythological interest tried to reconstruct ancient myth from fragmentary historical records, folklore materials and observations of contemporary cultic folk practices. The division line between Latvian and other Baltic – Lithuanian and Old Prussian – mythologies is blurred and was configured ad hoc by scholars according to their sources and conceptions of authenticity. The first ethnic Latvian publications on mythological matters are marked by patriotism and imagination.

The first Latvian fabulae – a semi-systematic catalogue of mythological beings – was published in 1636 by the theologian and clergyman Paul Einhorn in his Reformatio gentis Letticae in ducatu Curlandiae (1636). The genre was picked up later by Enlightement antiquarians. Mythological beings are described in Jacob Lange’s Vollständiges deutschlettisches und lettischdeutsches Lexicon (1777), which incorporates similar pseudo-pantheon lists published in the Gelehrte Beyträge zu den Rigischen Anzeigen in 1761 and 1764. Most extensively, fabulae featured in the appendix to Gotthard Friedrich Stender’s (1714–1796) Neue vollständigere lettische Grammatik, nebst einem hinlänglichen Lexicon, wie auch einigen Gedichten (2nd ed.; Mitau, 1783).

These early texts were descriptive and dismissive of their subject matter; but the material was explored afresh, with a different agenda, by Garlieb Merkel (1769–1850), who was inspired in equal measure by French Enlightenment radicalism and by early German Romanticism. Merkel was the first one to evoke an idyllic Golden Age before the 13th-century arrival of the Teutonic Order crusaders. Merkel conjured up the world of ancient Latvian deities in Die Vorzeit Lieflands: ein Denkmahl des Pfaffen- und Rittergeistes (1798-99) and Wannem Ymanta: Eine lettische Sage (1802).

Merkel’s writings obtained their greatest effect after some delay, in the Young Latvian circles of the second half of the 19th century. Parts of his works were regularly translated and published in periodicals such as the weekly Mājas viesis (“Home Guest”, founded in 1856). This journal also published articles of ethnographic and mythological interest by progressive Latvians, and it is in this context that the fabulae tradition acquired its Romantic Nationalist flavour. The tone was set by the Young Latvian writer and translator Juris Alunāns (1832–1864); his 1858-article Dievi un gari, ko senie latviešu pielūguši (“Gods and spirits once venerated by the ancient Latvians”, 1858) stands out among others from the period 1856-58, dealing with legends, water spirits, funerals, and customs. Alunāns made free use of Teodor Narbutt’s Mitologia litewska (“Lithuanian mythology”, 1835), that being the first part of Narbutt’s Dzieje starożytne narodu litewskiego (“History of the Lithuanian nation”). Narbutt (1784–1864) in turn relied on Simon Grunau’s “Prussian Chronicle” (c.1525), a highly controversial document that was frequently used to bolster claims for the putative existence of a primordial united Prussian-Lithuanian-Latvian nation, state, and religion.

One of the effects of this muddled source-tradition is the frequent crossover of myths and legendary figures between neighbouring tribes. That tendency was reinforced by the recent discovery of the kinship between the Baltic languages. It culminated in a unified Baltic mythological system as presented in the work of Wilhelm Mannhardt (1831–1880), e.g. his Letto-Preussische Götterlehre (1870). The connection with Lithuania and its prestigious medieval past held obvious appeal for the Young Latvians, who were faced with a dearth of written sources for Latvian history.

Alunāns’s pantheon was designed on the classical outlines of Greek/Roman mythology and often invokes publications on pre-Christian belief systems then in circulation. While he foregrounded the superstitious nature of myths he described, his mythical legends and pseudo-pantheon were aligned with a Merkel-derived “Golden Age” vision by the poet Mikus Krogzemis (“Mikus from the Krogzemji estate”, 1850–1879). Krogzemis, better known under his pen name Auseklis (which itself is mythological, referring to a putative dawn-deity identified with the Morning Star), relied on Stender’s fabulae as an authentic record of a genuine Latvian mythology. Although among the sixty mythological beings that feature in his poems only five are actually encountered in Latvian folklore and the majority are pure fiction, Auseklis bolstered the instrumentalization of a glorified Latvian past, both with poetical versions of folk legends (hierarchically rearranged and supplemented version of Alunāns’s fabulae) and with a long poem Čūsku tēvs Zalktis (“Zalktis the grass snake, father of snakes”, 1876).

In the last decades of the 19th century (later than in other European countries), Latvian nationalist mythography spawned a full-scale literary production, including the national epic Lāčplēsis (“Bear-slayer”, 1888) by Andrejs Pumpurs (1841–1902). Indebted to Merkel’s Wannem Ymanta, it features an extensive description of the council of Baltic gods; again, the pantheon comprises a mixture of Latvian and other Baltic sources. At the time of publication, Pumpurs’s epic was contested and largely overshadowed by the work of a rival: Jēkabs Lautenbahs-Jūsmiņš (1848–1928), the most prominent Latvian poet of the time, who was also a publisher, and ultimately professor at University of Tartu/Dorpat (1904) and at the University of Latvia (1919). Unlike most early mythographer-poets, he based his poetical work on a scholarly investigation of the material, which he published in several articles on particular deities and in a Latviešu mitoloģija (“Latvian mythology”, 1882, based on his lectures at Dorpat). The introduction to his poetry-collection Līga (1880) features a list of deities largely overlapping with those of Alunāns’s and Auseklis’s fabulae. The mythological past was also explored in his epic poems Zalkša līgava (“Bride of the grass-snake”, 1880) and Dievs un velns (“God and Devil”, 1885), and most extensively in the monumental epic Niedrīšu Vidvuds (“The tale of Vivuds from Niedrīši”, 1891). In 24 cantos of c.500 lines each, that work recycles diverse Latvian folklore materials, mostly legends, around a plotline derived mainly from Merkel. Unlike the writings of Auseklis and other Young Latvians, Lautenbahs-Jūsmiņš’ works were also appreciated by the Baltic-German learned elite, e.g. the Lettisch-Literärische Gesellschaft, whose members (August Bielenstein and Robert Auning among them) had also conducted mythological research.