Alexander I of Moldavia

Moldavia’s prince, Alexandru cel Bun (Alexander the Good), although brought to the throne in 1400 by the Hungarians (with assistance from Mircea I of Wallachia), in 1402 shifts his allegiances towards Poland, becoming a vassal of Władysław.

The name of the city of Iasi is first officially mentioned in a document about commercial privilege granted by the Moldavian Prince (Voivode) Alexandru the Good to the Polish merchants of Lvov in 1408.

However, as buildings older than 1408 existed and still exist (for example the Armenian Church originally believed to be built in 1395), it is believed that the city existed long before its first mentioning.

Moldavia’s Prince Alexander, called Alexander the Good (Alexander cel Bun), has expanded the bureaucracy system by creating the "Council of the Voivode", the Chancellory and by adding (in 1403) the institution of Logofăt—Chancellor of the official Chancellery.

During his reign, he has introduced new fiscal laws, by adding commercial privileges to the traders of Lviv (1408) and Kraków (1409), improved the situation of the trading routes (especially the one linking the port of Cetatea Albă to Poland), strengthened the forts guarding them, and expanded the Moldavian ports of Cetatea Albă and Chilia.

Alexander’s main concern is to defend the country in wars against superior armies.

To this end, he has forged a system of alliances with Wallachia and Poland, generally against Hungary (although he had been backed to the throne by Sigismund of Hungary).

In 1402, he had become a sworn vassal of Jogaila, the King of Poland.

The treaty is renewed in 1404 and 1407.

The forces of Poland-Lithuania, as the union of Poland and Lithuania begins to be called, led by Jogaila, break the power of the Teutonic Knights on July 15, 1410, at the Battle of Tannenberg, sometimes called the Battle of Grunwald/Grunfelde (the conflict’s location lies between the two East Prussian villages of Grunwald and Tannenberg/Stebark), thereby checking the Knights' eastward expansion along the Baltic.

The order’s grand master and the majority of its commanders are killed during the ten-hour battle.

The defeat of the Teutonic Knights is resounding.

About eight thousand of the Order’s soldiers have been killed and an additional fourteen thousand taken captive.

According to Teutonic payroll records, only fourteen hundred and twenty-seven men reported back to Marienburg to claim their pay.

Of twelve hundred men sent from Danzig, only three hundred returned.

According to different sources, some two hundred or four hundred brothers of the Order were killed, including much of the Teutonic leadership—Grand Master Ulrich von Jungingen, Grand Marshal Friedrich von Wallenrode, Grand Komtur Kuno von Lichtenstein, Grand Treasurer Thomas von Merheim, Marshal of Supply Forces Albrecht von Schwartzburg, and ten of the komturs.

Markward von Salzbach, Komtur of Brandenburg (Ushakovo), and Heinrich Schaumburg, voigt of Sambia, are executed by order of Vytautas after the battle.

The bodies of von Jungingen and other high-ranking officials are transported to Marienburg Castle for burial on July 10.

The bodies of lower-ranking Teutonic officials and twelve Polish knights are buried at the church in Tannenberg.

The rest of the dead are buried in several mass graves.

The highest-ranking Teutonic official to escape the battle is Werner von Tettinger, Komtur of Elbing (Elbląg).

Polish and Lithuanian forces take several thousand captives.

Among these are Dukes Konrad VII of Oels (Oleśnica) and Casimir V of Pomerania.

Most of the commoners and mercenaries are released shortly after the battle on condition that they report to Kraków on November 11, 1410.

Only those who are expected to pay ransom are kept.

Considerable ransomsare recorded; for example, the mercenary Holbracht von Loym had to pay sixty times the number of one hundred and fifty Prague groschen, amounting to more than thirty kilograms of silver.

The Polish and Lithuanian forces and the troops of King Alexander the Good of Moldavia delay their attack on the Teutonic capital in Marienburg (Malbork) after the battle of Grunwald  remaining on the battlefield for three days and then marching an average of only about fifteen kilometers (nine point three miles) per day.

The main forces do not reach heavily fortified Marienburg until July 26.

This delay gives Heinrich von Plauen enough time to organize a defense.

Only eight castles remain in Teutonic hands.

The besiegers of Marienburg had expected a speedy capitulation and are not prepared for a long-term siege, suffering from lack of ammunition, low morale, and an epidemic of dysentery The Knights appeal to their allies for help, and Sigismund of Hungary, Wenceslaus, King of the Romans, and the Livonian Order promise financial aid and reinforcements.

Jogaila also sends his troops to other Teutonic fortresses, which often surrender without resistance, including the major cities of Danzig (Gdańsk), …

…Thorn (Toruń), and …

…Elbing (Elbląg).

The siege of Marienburg is lifted on September 19.

The Polish–Lithuanian forces leave garrisons in the fortresses they have taken, and return home.

However, the Knights quickly recapture most of the castles.