Israel Sieff, Baron Sieff

In the early 1930s, Sieff went to the United States and spent several weeks in the merchandise development of Sears to gain practical knowledge to improve the company.

[2] When Simon Marks died in December 1964, Sieff became the chairman and joint managing director of the company.

The immense practical genius of Lord Marks balanced the percipient, sensitive fascination with any piece of pioneering which was characteristic of Sieff.

He was from the beginning deeply interested in all the social and economic implications of commerce on the scale with which he now found himself involved, and introduced many novelties in the relations of the firm with their customers, their employees, and their suppliers.In 1918, Sieff was a member of the Zionist Commission which visited Palestine under the leadership of Chaim Weizmann.

They had three sons and a daughter:[1] The death of their son Daniel, who intended to be a scientist, at age 17 led Sieff — and with the financial support of his business partners and relatives by marriage, the Marks and Sacher families — to endow the 1934 creation, by Chaim Weizmann, of the Daniel Sieff Research Institute in Rehovot in present-day Israel.