Maybe description?:
In July 1331 Bohemian king Johann von Luxemburg and grand master of the Teutonic Order Luther von Braunschweig established plans of joint military action against Wladyslaw Lokietek (Polish king). Teutonic army was to invade Poland from the north while Bohemia from the south across Silesia. Both sides agreed that their armies would meet near Kalisz (second largest town of the province of Greater Poland after Poznan).
The strategic goal of Johann von Luxemburg was to conquer Greater Poland, to which he claimed his rights as heritage after Przemyślidzi dynasty. It must be added that Bohemian king in his own documents called himself "king of Poland", while he called Wladyslaw Lokietek just "king of Cracow". Most of Polish dukes of the fragmented for several duchies Mazovia - which was independent from the Kingdom of Poland - supported the Teutonic Order during that war.
The Grand Master wanted to capture Cuiavia and northern parts Poland.
Mazovian dukes would probably expand their duchies into Lesser Poland (including Cracow).
Teutonic invasion army reinforced by some Mazovian contingents crossed the Polish border sooner than their Bohemian allies. They plundered the Lands of Sieradz and Leczyca and approached to Kalisz, attempting to capture the town. After several days of futile siege and waiting for arrival of Bohemian forces, they retreated from the walls of Kalisz and marched north in order to besiege Brzesc Kujawski and to capture Cuiavia.
During that Teutonic withdrawal from Kalisz Polish main forces (ca. 5000 strong) followed and chased them up to the area of Radziejow and Plowce. Polish forces harrased the Teutonic army during that march but Lokietek's army was less numerous than their enemies (ca. 7000 strong) and thus had to wait for a good opportunity and favourable conditions to attack and destroy the Teutons.
In the meantime Bohemian invasion was delayed by problems with the so called Anti-Luxemburgian League (Hungary and Austria). Their army also had to bypass the borders of the independent Silesian Duchy of Swidnica which was ruled by Bolko II (from Piast dynasty), who sympathized with Poland.
Finally Bohemian army marched across Wroclaw, Glogow and Koscian and approached Poznan. After approaching Poznan (the main town of the Greater Poland province), initial attempts to capture the city failed and the Bohemian army had to start a regular siege.
In the meantime, on 27 September 1331, Lokietek, who lead the main Polish army - 5,000 men strong - finally decided to destroy the Teutonic army (7,000 men strong but divided into 3 columns during its march) and delivered them a battle near the village of Plowce.
Before the battle king Wladyslaw - concerned over his son's and successor's (Casimir) live - sent him back so he didn't fight in the battle.
In the first phase of the battle, Polish forces ambushed the rear column of the Teutonic army and destroyed it completely. Alarmed by remnants of that column, the remaining two columns hastily turned back to the battlefield and counterattacked the Poles.
After fierce and long battle during which both sides suffered heavy losses, the less numerous Polish army detached from the enemy in good order and withdrew from the battlefield to regroup, taking away a few hundred captured Teutons with them. The Teutons - who also held a few hundred prisoners - too exhausted and decimated to chase the Poles, quickly murdered all prisoners and hastily retreated back to their country.
Poles were not any better and also slaughtered most of Teutonic prisoners.
Bishop of Cuiavia - Maciej - who organized burial after the battle, counted bodies of 4187 dead "Christians" on the battlefield. He didn't write how many of the fallen were Poles and how many were Teutons but we can see that casualties of both sides were considerable.
After receiving news about the Teutonic "defeat" at Plowce (in fact the battle was inconclusive in tactical sense - but it was definitely a strategic victory for the Poles), Johann von Luxemburg also resigned from further attempts of capturing Poznan and retreated back to Bohemia.
As the result enemy plan of partitioning Poland failed.
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Regarding estimations of forces of both sides in the battle of Plowce:
Numbers generally range from 6300 to 7000 Teutons against 4500 to 5000 Poles.
So around 35% - 40% of all participants of the battle were killed (4187).
Battle was depicted in a movie:
http://www.youtube.com/watch?v=aouKLHgjQqI
Wikipedia:
http://en.wikipedia.org/wiki/Battle_of_Płowce