Editing History of Lithuania (section)

====Algirdas and Kęstutis====
[[File:Algierd. Альгерд (A. Guagnini, 1578).jpg|thumb|left|16th-century image of [[Algirdas]], one of the great rulers of 14th-century Europe]]
Around 1318, Gediminas' elder son [[Algirdas]] married [[Maria of Vitebsk]], the daughter of Prince Yaroslav of [[Principality of Vitebsk|Vitebsk]], and settled in [[Vitebsk]] to rule the principality.<ref name="Ochmański 53-55"/> Of Gediminas' seven sons, four remained pagan and three converted to Orthodox Christianity.<ref name="Baczkowski 55-61"/> Upon his death, Gediminas divided his domains among the seven sons, but Lithuania's precarious military situation, especially on the Teutonic frontier, forced the brothers to keep the country together.<ref name="Ochmański 55-56">Ochmański (1982), pp. 55–56</ref> From 1345, Algirdas took over as the Grand Duke of Lithuania. In practice, he ruled over Lithuanian Ruthenia only, whereas [[Lithuania proper]] was the domain of his equally able brother [[Kęstutis]]. Algirdas fought the Golden Horde Tatars and the Principality of Moscow; Kęstutis took upon himself the demanding struggle with the Teutonic Order.<ref name="Baczkowski 55-61"/>

The warfare with the Teutonic Order continued from 1345, and in 1348, the Knights defeated the Lithuanians at the [[Battle of Strėva]]. Kęstutis requested King [[Casimir III the Great|Casimir]] of Poland to mediate with the pope in hopes of converting Lithuania to Christianity, but the result was negative, and Poland took from Lithuania in 1349 the [[Halych]] area and some Ruthenian lands further north. Lithuania's situation improved from 1350, when Algirdas formed an alliance with the [[Tver#Grand princedom|Principality of Tver]]. Halych was ceded by Lithuania, which brought peace with Poland in 1352. Secured by those alliances, Algirdas and Kęstutis embarked on the implementation of policies to expand Lithuania's territories further.<ref name="Ochmański 55-56"/>

[[File:Authentic Seal of Kęstutis.jpg|thumb|Seal of [[Kęstutis]]]]
[[Bryansk]] was taken in 1359, and in 1362, Algirdas captured Kyiv after defeating the Mongols at the [[Battle of Blue Waters]].<ref name="Davies 392"/><ref name="Lukowski 38-39"/><ref name="Ochmański 55-56"/> [[Volhynia]], [[Podolia]] and [[left-bank Ukraine]] were also incorporated. Kęstutis heroically fought for the survival of ethnic Lithuanians by attempting to repel about thirty incursions by the Teutonic Knights and their European guest fighters.<ref name="Baczkowski 55-61"/> Kęstutis also attacked the Teutonic possessions in Prussia on numerous occasions, but the Knights took [[Kaunas]] in 1362.<ref name="Ochmański 56-58">Ochmański (1982), pp. 56–58</ref> The dispute with Poland renewed itself and was settled by the peace of 1366, when Lithuania gave up a part of Volhynia including [[Volodymyr-Volynskyi|Volodymyr]]. A peace with the Livonian Knights was also accomplished in 1367. In 1368, 1370 and 1372, Algirdas invaded the [[Grand Duchy of Moscow]] and each time approached [[Moscow]] itself. An "eternal" peace (the [[Treaty of Lyubutsk]]) was concluded after the last attempt, and it was much needed by Lithuania due to its involvement in heavy fighting with the Knights again in 1373–1377.<ref name="Ochmański 56-58"/>

The two brothers and Gediminas' other offspring left many ambitious sons with inherited territory. Their rivalry weakened the country in the face of the Teutonic expansion and the newly assertive Grand Duchy of Moscow, buoyed by the 1380 victory over the Golden Horde at the [[Battle of Kulikovo]] and intent on the unification of all Rus' lands under its rule.<ref name="Baczkowski 55-61"/>