The Lithuanian nobility () or szlachta of the Grand Duchy of Lithuania (, ) was historically a legally privileged hereditary elite class in the Grand Duchy of Lithuania and Polish Lithuanian Commonwealth (including during period of foreign rule 1795–1918) consisting of Lithuanians from Lithuania Proper; Samogitians from Duchy of Samogitia; following Lithuania's eastward expansion into what is now Belarus, Ukraine and Russia, many ethnically Ruthenian noble families (boyars); and, later on, predominantly Baltic German families from the Duchy of Livonia and Inflanty Voivodeship.Krzysztof Buchowski, Litwomani i polonizatorzy, p. 20–50, 2006 Białystok, Uniwersytet w Białymstoku,

Initially, the privileged social group of the Grand Duchy of Lithuania was called boyars. Boyars became part of the szlachta (nobility) during the Union of Horodło on October 2, 1413, initiating nobility in the Grand Duchy of Lithuania following the Western European model (with a hereditary system of heraldic identification), as well as an increase in the position of the Greater Lithuanian nobility. The Grand Duchy of Lithuania adopted Polish institutions of castellans and voivodes, and 47 selected boyars of Grand Duchy of Lithuania of the Catholic faith were adopted by Polish noble families and received Polish coats of arms.

Families of the nobility were responsible for military mobilization and enjoyed Golden Liberty; some were rewarded with additional privileges for success on the battlefield. In the Grand Duchy of Lithuania, ducal titles were mostly inherited by descendants of old dynasties while the relatively few hereditary noble titles in the Kingdom of Poland were bestowed by foreign monarchs. The Polish–Lithuanian Commonwealth had one of the largest percentages of nobility in Europe, with szlachta (nobility) constituting close to 10% of the population, but in some constituent regions, like the Duchy of Samogitia, it was closer to 12%. However, the high nobility was extremely limited in number, consisting of the magnates and later, within the Russian Empire, of princes.

Over time, the vast majority of the nobility of the Grand Duchy of Lithuania voluntarily became Polonized and recognized Polish national thought as a natural continuation of Greater Lithuanian national thought.

Cultural affiliation According to the Polish historian Grzegorz Błaszczyk, Lithuanian nobility doesn’t mean the same as the leaders of today's Lithuania, as the terms "Lithuanians" and "Lithuanian" have changed over the centuries. According to the Lithuanian historian Vytautas Spečiūnas, the Grand Duchy of Lithuania was formed on the basis of Lithuania proper, which is a part of the Eastern Balts ethnic territory. According to the Polish historian , already during the times of the Grand Duchy of Lithuania, Lithuania proper was a term designated to land where Lithuanians live. The Lithuanian Grand Duke Vytautas in his 11 March 1420 letter sent to Sigismund, Holy Roman Emperor, wrote about Samogitia that "it is and has always been the same Lithuanian land, because there is one language and the same inhabitants. The people of Samogitia have long called themselves as Lithuanians and never as Samogitians, and because of such identity (sic) we do not write about Samogitia in our letter, because everything is one: one country and the same inhabitants" (see also: Samogitian dialect, Lithuanian language).

As cultural homogenization and linguistic Polonization of the nobility progressed, the concept of Lithuanian began to mean simply regional difference within the uniform political nation of the Polish-Lithuanian Commonwealth. The main Polonizing factors, as in other areas of the First Republic of Poland, were the church, the manor and the city, where the lower social classes adopted and thereby took over the cultural patterns of the higher classes.

Already in 1576, seven years after the conclusion of the Union of Lublin, Augustyn Rotundus, a historiographer of Greater Lithuania at that time, wrote that the Lithuanian language previously used by some citizens of Grand Duchy of Lithuania was used by peasants, while the nobility widely adopted Polish. However, this process took place without orders or prohibitions, without coercion, mainly under the influence of civilizational domination and administrative influence (there is also no evidence of administrative coercion). On the other hand, Mikalojus Daukša in his 1599 Postil wrote that "Although, to be honest, there are few of us, especially the more noble ones, who do not know Polish and cannot read sermons written in Polish, in my opinion, there are mostly those who do not understand Polish or have only a poor knowledge of it."

Polonization processes led to the fact that already in the 17th century, Lithuanian landowners called themselves gente Lithuani, natione Poloni (Latin: Lithuanians by birth, Poles by nationality).Ochmański J, Historia Litwy, Wrocław-Warszawa 1982, s. 139. In 1697, in the entire Grand Duchy of Lithuania, at the request of the local Lithuanian nobility, Polish was introduced as the official language instead of the previously existing Ruthenian language.

In the 18th century, the Polonization of the lands within the borders of the Polish-Lithuanian Commonwealth was a completed process, and the Polonization of Vilnius was a state of affairs. Despite the lack of their own state, the conviction of the permanent nature of Lithuania's relationship with Poles and the territorial integrity of their common, although enslaved, homeland was strengthening in the minds of all Poles. In the lands of the former Polish-Lithuanian Commonwealth, the cultural unity of inhabitants was strengthening, and many traditionally understood Lithuanians discovered a modern national identity - they became Poles. However, that the described processes took place almost exclusively within the nobility and landed gentry and among the intelligentsia.

The fall of the Polish–Lithuanian Commonwealth and unsuccessful armed uprisings led to the strengthening of the Polonization processes of the small nobility of the Grand Duchy of Lithuania, identifying spiritually and culturally with Polish traditions. Post-uprising repression resulted in the Catholic Church becoming the mainstay of Polishness. Because the Catholic Church had a Polish character, it became an element integrating both the conscious classes and the popular masses, who began to identify with Polishness through their religion.

The January Uprising of 1863-1864 and the wave of post-uprising repressions were a great shock for the people of the former Grand Duchy of Lithuania. However, under the influence of painful experiences, the sense of community between Lithuanianness and Polishness became even stronger, and the belief in the identity of both elements became almost a patriotic axiom. Additionally, in the second half of the 19th century and at the beginning of the 20th century, the process of linguistic Polonization of the rural population accelerated rapidly, especially in the Vilnius region.

In the consciousness of the general Polish society at that time, the multi-ethnic heritage of the Polish-Lithuanian Commonwealth was increasingly identified simply with Polish heritage. Such views were held by the most active and opinion-forming layer of the emerging nation. The intelligentsia grew up in an atmosphere of supremacy of nobility culture, so they easily identified with it. It adopted the nobility's way of perceiving the world, even if it came from other social groups. According to a commonly accepted interpretation, the history of the "peoples" inhabiting the eastern lands of the former Polish-Lithuanian Commonwealth constituted an integral part of the history of Poles. The local "peoples" (especially Lithuanians and Belarusians) were perceived at best as "younger brothers", naturally subordinated to the Polish national interest. It was therefore necessary to educate them and guide them in the right direction, because they were not yet mature enough to make independent decisions. "Our Polish paternalism - writes Roman Wapiński - is firmly located in the East.

In the Second Polish Republic, Lithuanians lived mainly in the counties on the border with Lithuania: Święciany, Vilnius-Trakai and Suwałki, and almost all of them were rural people engaged in agriculture. At the beginning of the 20th century, descendants of former noble Lithuanians were most likely to call themselves Poles. Only a part of the nobility, openly referring to the traditions of historical Lithuania, trying to reconcile Lithuanianness with Polishness, called themselves "old Lithuanians", "historical Lithuanians" or "The Mickiewicz's" (i.e. - such as in Adam Mickiewicz, from the first words of the invocation from the poem Pan Tadeusz: "O Lithuania, my country ... " ). In turn, the representatives of the former "Semigalian people", now "nationalized", called themselves Lithuanians, additionally reserving the exclusive right to this term. However, attempts were made to create organizations of native Lithuanians of noble descent. On April 4, 1928, the Lithuanian Boyars Society () was established, which operated until 1940.

Upon adoption of the Act of the Re-Establishment of the State of Lithuania in 1990 and this way ending the Soviet occupation of Lithuania, the Royal Union of the Lithuanian Boyars () was established in Vilnius in 1994 which continues the interwar period Society traditions, perform legitimation processes of historical Lithuanian nobles, organize ceremonies of awarding acts of recognition of nobility and unites thousands of Lithuanian nobles. However, the criteria for belonging to the nobility of this organization are treated liberally, accepting members who can prove their descent only through the female line. Therefore, the Royal Union of the Lithuanian Boyars has no chance of acceptance by international associations.

According to Professor Grzegorz Błaszczyk, the heritage of the Grand Duchy of Lithuania belongs primarily to the descendants of old Greater Lithuanian families, most of whom were Polonized and still live in Poland today. The last representative of the great Lithuanian families living in today's Lithuania, Stefania Maria Romer, died in 2012. Meanwhile, in Poland, about 2,000 Polish families with Lithuanian origins live and use the Polish language, including the Radziwiłł, Czartoryski, Tyszkiewicz, Sanguszko, Sapieha, Giedroyć, Piłsudski, Puzyna, Woroniecki and Romer families.

The president of the Genealogical and Heraldic Society of Lithuania, Czesław Malewski, commented that currently there are no famous families left in Lithuania, and the functioning and competing associations of the Lithuanian nobility gather in their ranks representatives of the minor nobility, most often descending from their families on the distaff side.

History

Lithuania before formal Christianization Prior to the baptism by Mindaugas, lesser members of the nobility were called bajorai (singular - bajoras) and greater nobles, kunigai (singular - kunigas), related to the Old , meaning "king", or , usually translated as duke, . These positions evolved from tribal leaders and were chiefly responsible for waging wars and organizing raids operations into enemy territories. Following the establishment of a unified state, they gradually became subordinates to greater Dukes, and later to the King of Lithuania. After Mindaugas' death, all Lithuanian rulers held the title Grand Duke (), or king, which was the title sometimes used by Gediminas and several others.