During World War I, became chaplain of the Puławy Legion (formally the 1st Puławy Legion), formed in Puławy under the auspices of the Polish National Committee and fighting on the Russian side under the command of Polish officers. The Legion — after Tsar Nicholas II issued a decree banning the further organisation of Polish units, under the name of the 739th Nowo–Aleksandrya Troop — was sent to the front line fighting the Germans. After the Russian defeat in the Battle of Gorlice on 03.05.1915, it took part in clashes with the Germans on 19‐20.05.1915 at Pakosław near Iłża, on 15.06.1916 at the nearby Michałów, on 17.07.1915 at Władysławowo near Lipsk. Then, retreating from the German onslaught, it fought on 20.07.1915 at Kolonia Czeczelska near Zwoleń, on 20.08.1915 at Nurzec–station near Siemiatycze, where it suffered huge losses. On 10.09.1915 it fought another battle at Zelwa near Sejny, after which — already in a fragmentary state — it was withdrawn to Bobruisk in Belarus on 18.09.1915. There it was disbanded.

The German–Russian fighting front stabilized in eastern Belarus for several years. Then, in the autumn of 1915, on the basis of the Legion, the Polish Rifle Brigade was formed in Bobruisk, under Russian command (mainly Russified Poles who owed their entire careers to the Russians), of which became chaplain. In 03‐07.1916 it was on the fighting front, north of Baranovichi on the Shchara River, where during the Brusilov offensive — in the Belarusian section of the offensive, which was only of a demonstrative nature — it performed reconnaissance functions. The biggest battle in which it took part was the battle of Torczyca, c. 10 km north of Baranovichi, on 27.07.1916, after which the front stabilized again. In 01.1917, the Brigade was withdrawn from the front to the Kiev Military District and here on c. 21.02.1917 it was reformed into the Polish Rifle Division.

His further fate is unclear. May have been the chaplain of that Division, which — after the abdication of Tsar Nicholas II on 15.03.1917 and the fall of tsarism — fought in Ukraine against the troops of the Central Powers (Austria–Hungary and Germany), including on 08‐12.07.1916 at Kozova, c. 30 km west of Ternopil, and on 28.07.1917 at Husyatyn on the Zbruch River. Perhaps after 24.07.1917 was transferred, together with the Division, to the 1st Polish Corps under the command of General Joseph Dowbor–Muśnicki, and together with him — after the putsch in 11.1918 in Sankt Petersburg, when the Bolsheviks financed by the Germans took power — took part in the capture of Bobruysk on 03.02.1918.  1st Polish Co then — after the conclusion on 03.03.1918 by the Central Powers of a peace treaty with Bolshevik Russia in Brest — surrendered to German hands, which allowed most of the soldiers to return to their homeland, Poland.

However, he did not return to Poland. Remained in the areas controlled by the Russians — perhaps this happened in Ukraine, where the Polish Rifle Division fought. Perhaps at the beginning of 01.1918 made it to Kiev together with Colonel Lucian Żeligowski, who, wanting to continue the fight against the Germans, came into conflict with General Dowbor–Muśnicki, leaving the 1st Corps. Sources claim that died in Arkhangelsk, which would indicate that may have followed the appeal of General Joseph Haller, commander of the 2nd Polish Corps in Russia, who, after the capitulation of his Corps on 11.05.1918 to the Germans at Kaniv on the Dnieper in Ukraine, managed to avoid arrest by getting to Kiev and announcing his intention to form Polish units in the Murmansk region, in northern Russia, and to continue fighting on the side of the Entente Allies — there were both English and French expeditionary units there. On 10.07.1918, he issued a manifesto in which stated: „In our country under German occupation, there is no place to unfurl our banner [of independence]! Enough powerlessness! Down with slavery and the hypocrisy of neutrality. We want to be a free nation among free nations, in accordance with the slogan of Dąbrowski's legions: 'Free people are brothers'. In the fight for freedom against violence, the Polish army cannot hesitate. The national independent banner of Poland can only wave among the fighting armies of free nations of the allied states of the Coalition, grasped in the strong and reliable hands of a Polish soldier, enthusiastically raised into the vortex of battle. 'In them!', as the fathers used to say: 'For you, Poland, and for your glory', because this banner manifests the power of the national spirit! I therefore call on you, Polish soldiers, to join the ranks, to take up arms!” Getting to Murmansk, where General Haller intended to form the new 2nd Corps, required breaking through the territories controlled by the Bolsheviks, and they began to arrest and shoot the soldiers heading north (especially in Moscow and Nizhny Novgorod).

Reached, it seems, Arkhangelsk, but was allegedly murdered there by the Bolsheviks — it was probably before 31.08.

1918, when Arkhangelsk was captured by the British, with the participation of a Polish unit from Murmansk.

Fate unclear.

In the available sources (e.g. Wikipedia) the figure of Fr Vincent Mikołajtis, b.

06.01.1893 in Pilotiškės, ordained in 1915, next student in Sankt Petersburg, who, however, survived and died in 1967.

On the other hand in the Archdiocese of Warsaw, the priest was Fr Vladislav Mikołajtis, b.

10.12.1881, ordained in 1905, who in c. 1915, during the First World War, found himself „outside the archdiocese” and his further fate is unknown.