The
Lithuanian Civil War of 1389–92 involved the Teutonic Knights, the Poles, and the competing factions loyal to Jogaila and
Vytautas in Lithuania. Amid ruthless warfare, the grand duchy was ravaged and threatened with collapse. Jogaila decided that the way out was to make amends and recognize the rights of Vytautas, After negotiations, Vytautas became practically the ruler of Lithuania, a self-styled "Duke of Lithuania," under a compromise with Jogaila known as the
Ostrów Agreement. Technically, he was merely Jogaila's regent with extended authority.
Under Vytautas, a considerable centralization of the state took place, and the Catholicized
Lithuanian nobility became increasingly prominent in state politics. The centralization efforts began in 1393–95, when Vytautas appropriated their provinces from several powerful regional dukes in Ruthenia.
During Vytautas' reign, Lithuania reached the peak of its territorial expansion, but his ambitious plans to subjugate all of Ruthenia were thwarted by his disastrous defeat in 1399 at the
Battle of the Vorskla River, inflicted by the Golden Horde. Vytautas survived by fleeing the battlefield with a small unit and realized the necessity of a permanent alliance with Poland.
The original Union of Krewo of 1385 was renewed and redefined on several occasions, but each time with little clarity due to the competing Polish and Lithuanian interests. Fresh arrangements were agreed to in the "
unions" of
Vilnius (1401),
Horodło (1413),
Grodno (1432)...
In 1403,
Pope Boniface IX banned the Knights from attacking Lithuania, but in the same year Lithuania had to agree to the
Peace of Raciąż. It was the fourth(!) time, after the
Treaty of Königsberg (1384),
Treaty of Lyck (1390) and
Treaty of Salynas (1398) that Vytautas promised
Samogitia to the Knights. The territory was important to the Knights as it physically separated the Teutonic Knights in
Prussia from
its branch in
Livonia.
Secure in the west, Vytautas turned his attention to the east once again. The campaigns fought between 1401 and 1408 involved Smolensk,
Pskov, Moscow and
Veliky Novgorod. Smolensk was retained, Pskov and Veliki Novgorod ended up as Lithuanian dependencies, and a lasting territorial division between the Grand Duchy and Moscow was agreed in 1408 in the treaty of
Ugra.
The treaty with Knights was not stable and the situation soon changed with the decisive
Polish-Lithuanian–Teutonic War of 1409–1411 (inspired by the
second Samogitian uprising). Ultimately the Lithuanian–Polish alliance was able to defeat the Knights at the
Battle of Grunwald on 15 July 1410, but the allied armies failed to take
Marienburg, the Knights' fortress-capital. Nevertheless, the unprecedented total battlefield victory against the Knights permanently removed the threat that they had posed to Lithuania's existence for centuries. The
Peace of Thorn (1411) allowed Lithuania to recover Samogotia, but only until the deaths of Jogaila and Vytautas.
The
Union of Horodło (1413) incorporated Lithuania into Poland again, but only as a formality. In practical terms, Lithuania became an equal partner with Poland, because each country was obliged to choose its future ruler only with the consent of the other, and the Union was declared to continue even under a new dynasty.
The
dynastic link to Poland resulted in
religious, political and cultural ties and increase of
Western influence among the native Lithuanian nobility, and to a lesser extent among the
Ruthenian boyars from
the East, Lithuanian subjects. Catholics were granted preferential treatment and access to offices because of the policies of Vytautas, officially pronounced in 1413 at the Union of Horodło, and even more so of his successors, aimed at asserting the rule of the Catholic Lithuanian elite over the
Rus' territories. Such policies increased the pressure on the nobility to convert to Catholicism. Ethnic Lithuania proper made up 10% of the area and 20% of the population of the Grand Duchy.
Vytautas practiced religious toleration and his grandiose plans also included attempts to influence the Eastern Orthodox Church, which he wanted to use as a tool to control Moscow and other parts of Ruthenia. In 1416, he elevated
Gregory Tsamblak as his chosen Orthodox patriarch for all of Ruthenia. These efforts were also intended to serve the goal of global unification of the Eastern and Western churches. The Orthodox synod, however, would not recognize Tsamblak.
The
Gollub War with the Teutonic Knights followed and in 1422, in the
Treaty of Melno, the grand duchy permanently recovered Samogitia, which terminated its involvement in the wars with the Order. Vytautas' shifting policies and reluctance to pursue the Order made the survival of German
East Prussia possible for centuries to come. Samogitia was the last region of Europe to be Christianized (from 1413).
Under Vytautas a network of chanceries functioned, first schools were established and
annals written. Taking advantage of the historic opportunities, the great ruler opened Lithuania for the influence of the
European culture and integrated his country with European
Western Christianity.
Vytautas' greatest successes and recognition occurred at the end of his life, when the
Crimean Khanate and the
Volga Tatars came under his influence. Prince
Vasily I of Moscow died in 1425, and Vytautas then administered the Grand Duchy of Moscow together with his daughter, Vasily's widow
Sophia of Lithuania (mother of 10-year old Vasily II).
At the
Congress of Lutsk in 1429, Vytautas negotiated the issue of his crowning as the king of Lithuania with Holy Roman Emperor
Sigismund and Jogaila. That ambition was close to being fulfilled, but in the end was thwarted by last-minute intrigues and Vytautas' death. Vytautas' cult and legend originated during his later years and will continue for long years.
Following the deaths of Vytautas in 1430 and Jogaila in 1434, another civil war ensued, and Lithuania was ruled by rival successors. Afterwards, the Lithuanian nobility on two occasions technically broke the union between Poland and Lithuania by selecting grand dukes unilaterally from the
Jagiellonian dynasty. In 1440, the Lithuanian great lords elevated
Casimir, Jogaila's second son, to the rule of the grand duchy. This issue can be resolved by Poles electing Casimir as king.
Now, in 1444 Lithuania have to choose to stay catholic and “tolerate” 80% of country population or become orthodox and confront west Europe. Three strongest neighbors (Monastic orders, Poland and Muscovy) can be friends or rivals.
Teutonic order holds Old Prussian (Brothers of Lithuania) land. Lithuania Christianized and could live in peace with Knights but can the rivers of Old Prussian blood be forgotten and forgiven? Can Latvian brothers be left for Livonian “Mercy”?
Poland holds disputed Ruthenian land (Podole), this “historical friend” was that one who called Knights in to Baltic lands and from 1385 tried to establish “friendly” rule over Lithuania.
Muscovy, ruled by Vytautas’ grandson could be strong enough ally against other two, but are they going to forgive Smolensk and Kievan Rus’ lands?
It’s time to decide if Lithuania reached peak and now will shrink in size and power or it’s just a first step of growing glory.
). I suspect 
