Mieczyslaw fought in the September Campaign in Poland, under the command of General Maczek.  After evacuation from Poland, he fought in France in 1940, then evacuated to the UK.  He was part of the D-Day invasion force in 1944, and participated in the France and Belgium Campaigns with the 1st Polish Armoured Division, in the 10th Motorized Brigade.  He was wounded in Belgium, and sent to the UK to recuperate.  After the war, Mieczyslaw eventually settled in Canada.