Michael was the youngest of five children. His brothers were named Barnet and Ephraim and his sisters were named Malke Beile and Esther. The family surname was not always Marks – this was an anglicised name that the family adopted, with some sources suggesting that the family’s original surname was Markovich.
To escape increasing anti-Semitism in Russia, all five of Mordechai’s children emigrated to Great Britain or the United States. Barnet was the first of the Marks siblings to leave, followed by Michael, who was about 19 years old when he left Slonim in 1882. He travelled by train to Germany, then by ship to London’s docklands, with few possessions and little money.
Michael had expected to join his older brother Barnet in London, but discovered that Barnet had already left for America, where he remained and opened a general store. Michael heard that there was demand in Leeds for unskilled tailors, including at a firm called Barrans. He had just enough money for the train fare to Leeds, so he set off for the north to try to find work.
Michael’s other brother, Ephraim, also migrated to the UK in 1890, setting up his own small chain of Penny Bazaar shops including in Oldham, Stockport, Dublin and Dundee. By 1918 Ephraim’s business was doing badly and he closed or sold his shops; this included selling some shops to Marks and Spencer, the company founded by his younger brother Michael.