Tesco was founded by Jack Cohen, who served with the Royal Air Force during the First World War. After returning in 1919, 21 year old Jack invested 30 pounds of his reward for military service to buy surplus food stockpiles and he opened a little stall in East London. On the first day he had a four pound turnover and one pound profit. Little by little, his business started to boom and Jack expanded to other markets all over London. He also began wholesale trade.
The first line of Cohen brand goods placed on the market was Tesco tea. In 1924, the name which the company later took on as its corporate name emerged. The name Tesco contains the initials of the owner of the firm, Mr. T. E. Stockwell, who supplied the firm with tea and of the initials of Jack�s surname � Cohen. Towards the end of the twenties, instead of stall trade Jack focused on window shop trade taking place on the main street. In 1929, the name Tesco first flared above a shop provided with a lock in North London (Burnt Oak, Edgware).
from the Tesco website