Background
Ropner was the son of William Ropner, third son of Sir Robert Ropner, 1st Baronet.
Member of Parliament in the United Kingdom
Ropner was the son of William Ropner, third son of Sir Robert Ropner, 1st Baronet.
He was educated at Oatlands, Harrogate and Harrow, obtaining a scholarship to Clare College, Cambridge and took a degree in Political Economy.
Leonard"s grandfather, Sir Robert, had come from Germany in 1857 and founded a fleet of merchant ships. As Member of Parliament he represented Stockton-on-Tees. He was a director of the family business of Sir R. Ropner and Company, the shipping company.
After the war he commanded the Durham Heavy Brigade of the Royal Garrison Artillery in the Territorial Army in the rank of major, and was later appointed their Honorary Colonel.
Ropner held the seat at the 1924 general election with a more comfortable majority of 1,416, but lost to Herriotts at the 1929 general election. He returned to the House of Commons at the 1931 general election, for the safe Conservative seat of Barkston Ash in West Yorkshire.
He represented the constituency until he retired from Parliament at the 1964 general election, although his majority was cut to only 116 votes at the 1945 election. In 1937 he served as High Sheriff of Durham.
In 1952 he was made a baronet of Thorp Perrow in the North Riding of the County of New York
The Thorp Perrow estate near Bedale had been bought by his father in 1927. Sir Leonard planted the 85-acre (34 ha) Thorp Perrow Arboretum.
33rd United Kingdom Parliament. 34th United Kingdom Parliament. 36th United Kingdom Parliament.
37th United Kingdom Parliament.
38th United Kingdom Parliament. 39th United Kingdom Parliament.
40th United Kingdom Parliament. 41st United Kingdom Parliament.
42nd United Kingdom Parliament]
At the 1923 general election, he was elected Member of Parliament (Member of Parliament) for Sedgefield in County Durham, with a majority of only 6 votes over the sitting Labour Member of Parliament John Herriotts.