Leonid Iwanowitsch Kubbel 

(Russia, 25.12.1891 OS = 6.1.1892 NS - 18.4.1942).

Biography
Leonid Kubbel was a chemical engineer by profession. His two brothers were also involved in chess composition. Arwid Kubbel published around 500 compositions of the Bohemian School, mainly three-move pieces. The younger Yevgeny Kubbel (* 23 October 1894; † 1942) composed over 150 chess problems, mainly two-mover chess problems.

Leonid Kubbel and his brother Yevgeny died during the Leningrad blockade and were buried in a mass grave with other victims of the blockade. Arwid was arrested on 21 November 1937. The arrest was kept secret and later the false report was spread that he had died of nephritis in a Siberian gulag. In fact, he was shot on 11 January 1938 and later rehabilitated during the thaw.

The Kubbels' ancestors were German.

Chess composition
Leonid Kubbel composed around 2300 chess problems (mainly three-move pieces) and more than 500 endgame studies. Over 500 compositions received awards, including 120 first prizes. Kubbel headed various chess columns and influenced the development of chess composition with his views.

According to his book 150 endgame Studies, he created his first study at the age of 13 in 1904. Initially, Kubbel represented positions of the Old German and Bohemian schools, but at the end of the 1920s he came to the conclusion that many combinations could not be represented artistically with pattern mates. Until 1911, he mainly composed chess problems. Löwenfisch considered them to be "perfect artistic products". This was followed by an interruption of three years, and Kubbel did not compose again until 1914. From 1918 onwards, he composed almost exclusively studies. 

However, they did not appear until 1921 in "Listok Petrogubkommuny". Kubbel was concerned with the ideas of the New German School. Löwenfisch praised the structure, economy and purity of Kubbel's studies, which in Löwenfisch's opinion had developed a style of their own.

Source: Germain Wikipedia

Others: 4 endgame studies are shown on the Dutch Website arves.org. Editor is Peter Boll.