Estonia, Latvia and Lithuania are three countries with three unrelated trajectories before 1800 and two unrelated language families, and almost every English-language book treats them as a single subject. That is defensible and it is also misleading, and knowing where each is true is the first thing a reading order here has to teach you.
What justifies the grouping: from 1918 onward the three genuinely share a timetable — independence, annexation in 1940, German occupation in 1941, Soviet reoccupation in 1944, restored independence in 1991 — and a serious body of scholarship is written regionally. What it obscures: Lithuania was a vast medieval Catholic grand duchy that reached the Black Sea, while Estonia and Latvia spent six centuries under a German landlord class and became Lutheran; and Estonian is Finno-Ugric, closer to Finnish than to Latvian or Lithuanian, which are Indo-European. Hold both facts at once for the rest of the path.
Three countries, one shelf
Andres Kasekamp's A History of the Baltic States is the most current and readable regional single volume, and the clearest on what the three do and do not share. Andrejs Plakans's A Concise History of the Baltic States is the Cambridge volume — longer, and stronger on the early modern period and on social structure. Kasekamp first, Plakans as the fuller version.
Crusaders, landlords and a grand duchy
Read this stage as three histories, because this is where they diverge hardest. Eric Christiansen's The Northern Crusades is the standard account of the thirteenth-century conquest and Christianisation of the eastern Baltic, and the origin of the German presence that shapes everything afterwards in the north. S. C. Rowell's Lithuania ascending covers the rise of still-pagan Lithuania into a major European power between 1295 and 1345, and corrects any account that treats the Baltic as three small peoples to whom things happened.
Then the two national histories. Plakans's The Latvians is strongest on serfdom, the Baltic German estate order and the nineteenth-century awakening; Toivo Raun's Estonia and the Estonians is the standard English history of Estonia. Read them together, and come out able to explain why the Latvian and Estonian national movements began as revolts against a landlord class while Lithuania's began as the recovery of a lost empire.
Twenty years of independence
All three declared independence in 1918, fought to keep it, broke up the estates through land reform, and had slid into authoritarian rule by the late 1930s. John Hiden and Patrick Salmon's The Baltic nations and Europe is the best single account of how the republics were made and how they were abandoned. Lithuania in European politics, by Alfonsas Eidintas and Vytautas Zalys, covers the first Lithuanian republic including the Vilnius dispute with Poland and the Klaipeda question; Lithuania's interwar problems were genuinely unlike its neighbours' and get compressed in the regional surveys. Read the period on its own terms: the 1991 restorations claimed legal continuity with precisely these states.
1940, 1941, 1944 — the occupations and the accusations
The secret protocol to the Molotov-Ribbentrop pact assigned the three states to the USSR. Annexation in 1940 was followed in June 1941 by mass deportations to Siberia and, days later, by the German invasion, which many Balts initially welcomed. Over ninety per cent of Lithuania's and Latvia's Jewish populations were murdered, and local auxiliary units — the Arajs Kommando in Latvia, Lithuanian police battalions — took part directly; that participation is documented. The Soviet reoccupation, the deportations of 1949 and the Forest Brothers insurgency then produced a competing set of grievances.
The live dispute is the double genocide framing. Its strongest form: two totalitarian regimes occupied these countries in succession, both committed mass murder and mass deportation against their populations, and a memory politics that commemorates one while treating the other as a footnote is neither honest nor bearable to families deported to Siberia. The objection, pressed by many Holocaust historians: treating the two as equivalent obscures the scale of the Holocaust and the local participation in it, and in practice converts perpetrator nations into victim nations. Both positions are held seriously, and this guide adjudicates neither.
Four books. Romuald Misiunas and Rein Taagepera's The Baltic States, years of dependence, 1940-1990 is still the standard scholarly account of the Soviet period, the deportations and the armed resistance. Prit Buttar's Between giants is operational military history of 1939 to 1945, including the Latvian and Estonian units raised on both sides — a factual floor under the moral arguments. Herman Kruk's Diary of the Vilna ghetto was kept by the ghetto's librarian until shortly before his murder in 1944 and survived buried; Vilnius was the Jerusalem of Lithuania and this is its destruction from inside. Modris Eksteins's Walking since daybreak reconstructs his own Latvian family's flight westward and refuses to make anyone in it purely a victim.
Singing them back, and what came after
Priit Vesilind's The singing revolution is the most direct account of how Estonian song festivals became the vehicle of a movement that overturned Soviet rule without violence, alongside the Baltic Way human chain of some two million people in August 1989. Anatol Lieven's The Baltic Revolution, written on the ground as it happened, remains the sharpest analysis of the three independence movements and of the citizenship questions they were storing up: Estonia and Latvia restored citizenship on the basis of pre-1940 continuity, leaving large Russian-speaking populations, many of them born there, as non-citizens. That dispute is still running.
The full ordered path, with study plans, is the history of the Baltic states reading path.