The region is called Podlasie, Podlasko or Podlasze in Polish, Palenkė in Lithuanian, Padliašša (Падляшша) in Belarusian, Podljas’e (Подлясье) in Russian, פּאָדליאַשע Podlyashe in Yiddish, and Podlachia in Latin.

The origin of this name is apparently in East Slavic, probably Old Ruthenian ljax, as the descendants of the Proto-Slavic word *lęxъ 'Pole' are most widespread there; there is no trace of nasalisation as would be expected in a native Polish word, but instead the typically East Slavic reflex -ja-, betraying the non-Lechitic origin.

[4] It was created by combining the coats of arms of Poland (white eagle albeit without a crown) and Lithuania (mounted armoured knight holding a sword and shield with the Jagiellonian Double Cross).

[8] In the 13th century, the Yotvingians were driven out of Podlachia by Bolesław V the Chaste and Leszek II the Black, and the region was repopulated by Poles from Masovia, including minor nobility.

[9] In the 14th century, Polish King Casimir III the Great granted the southern part to Lithuania.

Knyszyn was the favorite residence of King Sigismund II Augustus, who died there in 1572, ending the reign of the Jagiellonian dynasty in Poland.

[11] Polish Renaissance writer Łukasz Górnicki, after his appointment as starost of Tykocin in 1572, resided and wrote many of his works in Lipniki in Podlachia.

[14] Petty nobility often cultivated their land on their own, and there were many places where the nobility had no serfs, making certain parts of Podlachia, according to Polish historian, geographer and ethnographer Zygmunt Gloger, the place with the highest percentage of free agricultural population in Europe in the feudal era.

[15] Polish nobles in Podlachia became so numerous that from the 16th century some migrated to other regions, including Lesser Poland and Lithuania, where they often made significant fortunes.

[20] In the 18th and 19th century the private town of Białystok became the main center of the region, thanks to the patronage of the Branicki family and the development of the textile industry.

[21][22] Białystok was a regional brewing center with 33 breweries as of 1771, with the Podlachian Beer now listed as a protected traditional beverage by the Ministry of Agriculture and Rural Development of Poland.

[20] Following the 1795 Third Partition of Poland, Podlachia was divided between the Kingdom of Prussia and the Habsburg monarchy (Austrian Empire from 1804), with the Bug forming the border between them.

In theory this kingdom was created as an autonomous entity but in practice its separate laws and freedoms were simply ignored by the Emperors and control was steadily centralised, particularly following the November and January Uprisings (1830–31, 1863–64).

In the second half of the 19th century, Białystok grew into a significant center of the textile industry, the largest after Łódź in then-partitioned Poland.

As a result of the uprising, in 1867 Congress Poland was formally absorbed into Russia as the Vistula Land (Privislinsky Krai), although the Kingdom still nominally existed.

According to the Russian Imperial Census of 1897, the most spoken languages in the Siedlce Governorate were Polish (66.13%), Yiddish (15.56%) and Ukrainian (13.95%).

During World War I the area was occupied by the German Empire, with most of the Vistula Land falling under the Government General of Warsaw (later the Central Powers puppet Kingdom of Poland) while the areas further east, including Białystok and the Suwałki Governorate, fell under Ober Ost.

Although the border agreed upon in the Pact would have given all of Podlachia to the Soviet Union, the final border agreed upon in the German–Soviet Boundary and Friendship Treaty signed after the invasion gave the southern part to the Nazi General Government, while the northern part of Podlachia was annexed by the Soviet Union as the Belastok Region of the Byelorussian SSR.

The Polish resistance movement was active in the region, with Białystok becoming the seat of one of the six main commands of the Union of Armed Struggle in occupied Poland (alongside Warsaw, Kraków, Poznań, Toruń and Lwów).

[29] Under German occupation, the population was subjected to mass arrests, executions and deportations to forced labour, concentration camps and Nazi ghettos, whereas under Soviet occupation the population was subjected to mass arrests, executions, deportations to forced labour in Siberia, Central Asia and the Far North.

[41] Orthodox autochthonous inhabitants are known as khakhly (without any negative connotations, though today in Ukraine it is known as an ethnic slur for Ukrainians).

In 1875, Russians forbade this rite in the southern portion as well, and all Greek-Catholic inhabitants were forced to accept the Eastern Orthodox faith.

However, the resistance of the local people was surprisingly strong and Ruthenian speakers from this area rejected the separation from the Pope.

In reaction to these measures, the Ruthenians of southern Podlachia began to identify themselves with the national movement of the Roman Catholic Poles.

To preserve the full communion with the Pope, they changed their rite from Eastern to Latin before the compulsory conversion of Greek Catholics into Orthodox.

In 1912, Russian authorities issued a tolerance edict that made it possible to change confession from Orthodox to Roman Catholic (but not to Greek-Catholic, which had been completely deleted).

In 1992, the Union of Tatars of the Republic of Poland (Związek Tatarów Rzeczypospolitej Polskiej) with autonomous branches in Białystok and Gdańsk began operating.