After the defeat of the First Uprising in August 1919, the Allied army arrived in Silesia, which reduced the scale of the German terror waged on Poles and the organizations they set up. In October 1919, German troops were withdrawn from Silesia.
Already in March 1921, steps were taken on the Polish side to strengthen the garrisons along the border with Upper Silesia and to transfer weapons to Upper Silesia. The border has also been secretly crossed by a telegraphic company to organize communication in the event of a further uprising. In response, Germany expanded Selbstschutz. The French army took action against it, which disbanded some of the aspiring troops. An interview was of great importance to both sides. During the night between 29 and 30 April, the Polish Command discovered that Poland's position in the Internally Plebiscite Commission is becoming weaker.
In the last days of April another wave of strikes was spilt in Upper Silesia and social tension was increasing. Given the possibility of a spontaneous explosion of clashes and worrying information from the Internally Plebiscite Commission, Wojciech Korfanty decided to convene the meeting of Polish political and military leaders in Bytom. During that time, the decision was taken to initiate the uprising.
On 2 May, the general strike of polish miners and workers began. On the same day, the Lieutenant Colonel of the Polish Military Organization (POW) Maciej Miłżyński, aka Nowina-Doliwa passed to Warsaw the decision to start the uprising.
The uprising began on the night of 2 to 3 May. Korfanty also announced himself as a dictator of the uprising. "Victory will be achieved at all costs, and there is no such power in the world that could put us in German’s irons again," he wrote to the compatriots on 3 May.
The Uprising began with the taking over of telephone and telegraphic networks. The sappers’ branches sent most bridges at the border of Upper Silesia and Germany. Many soldiers taking part in this action were unable to reach the remaining insurgent forces and died in fights or were murdered by the Germans.
In mid-June, the Allied army occupied further locations. In this way, the forces of the fighting parties were effectively distributed. On 16 June, the Polish Command issued an order announcing the cessation of hostilities.
"The insurgents! The uprising reached its closest goal. Today there is no German as a representative of any authority, even a subsidiary of the allies, on the part of Upper Silesia that you have won. The Polish people of Upper Silesia became a strong foot on their land as their owner. The boundaries of your area are secured by the Allied army. German troops withdraw from our front outside the plebiscite area under the control of the coalition authorities. [...] The coalition’s decision about our country will soon be taken. You proved to them that Upper Silesia is Polish."
At the same time, Polish authorities responded: "Our suffering will end, and the Polish Silesia liberated from the German yoke will be able to work on its own development and for the good of the great, now United homeland."
The process of acquiring control over the allocated area ended symbolically on 16th July 1922, when a document commemorating that moment was signed in Katowice (Upper Silesia Act of Accession).
The results of the struggle for Silesia were welcomed by the majority of the population. In the centuries called to celebrate victory resolutions were passed, in which it was ensured that the rest of Upper Silesia would return to Poland.
“The miracle over the Vistula saved Poland from a loss, the miracle over the Oder gave to Poland Silesia. The miracle over the Vistula and the miracle over the Oder were not created by any dictator, no powers who took responsibility for the fate of the nation, but by the spirit of the nation, its national solidarity, the spirit of citizenship and the sense of responsibility of each citizen," said Wojciech Korfanty.
Source: Poland Daily 24, niezalezna.pl, pap.pl