Hans Fahrni (* 1 October 1874 in Prague; † 28 May 1939 in Ostermundigen, Switzerland) was a Swiss chess master and chess composer of endgame studies

Chess:

In 1908 he won a match against Salwe 3-1 with a draw. In Munich, where he had moved, he drew a match against Alekhine in September 1908 (+1 =1 -1) and won a four-master tournament the following year ahead of Tartakower, Alapin and Spielmann.

His undoubted greatest success, however, came in San Remo in 1911, when he won ahead of Lowtzky, Forgacs, Kostić, Przepiórka, Gunsberg, Richard Réti etc.

Fahrni was the first Swiss professional chess player to excel in numerous areas of chess. In 1911, for example, he set a world record in simultaneous play in Munich by becoming the first master to play more than one hundred games simultaneously. He was also active in correspondence chess and as a composer of problems and many endgame studies.

To earn a living, he occasionally worked as a sales representative and played for small stakes in cafés. In his memoirs, Carl Carls described him as the greatest chess idealist he had ever met, while Ludwig Bachmann described him as a daring attacking player whose play was not profound enough to be more successful.

Writer of 2 chess books:

Fahrni also wrote chess columns and wrote two chess books: Das Endspiel im Schach (Leipzig 1917) and Die Aljechin-Verteidigung (Bern 1922).

During the First World War, he was admitted to a psychiatric clinic for the first time and soon afterwards deported to his home country. After 1917, he spent the remaining years of his life in the Waldau sanatorium near Bern.

His best historical Elo rating was 2557 in December 1906, and Fahrni achieved his best ranking (with a slightly lower score) in January 1917 as number 20 in the world.

Source: Wikipedia

On the Dutch Website ARVES is written:

"He was born in Prague in 1874 and was according to Richard Forster's anniversary Book of the SG Zurich the first Swiss professional chess master.
According to a broken education as photographer and a disease caused dismissal from the aliens' legion the fascination of chess grabbed him.
His initial successes were in Switzerland, before he emigrated to Germany, where he became in 1904 master of the German Schachbund. In 1909 he was with 2506 historical rating points 19th of the world ranking.
He won against Tartakower, Nimzowitsch, Spielmann and Tarrasch. He celebrated his biggest success in 1911 with the first place in the master tournament of San Remo. In the same year, he also set up a simultaneous world record.

The outbreak of the First World War ruined his existence. That was probably the cause of his illness, the reason why he was deported back from Germany to Switzerland,
where he remained until his death in 1939 in a nursing home in Waldau near Bern.

Chesscomposing
Back in Switzerland Hans Fahrni was intensively involved with art and chess composition.  He was the first Swiss composer to compose over 150 studies, often close to over the boardchess, 83 of which together with the Dutchman Johannes Willem Keemink.

He also published two books: "Das Endspiel im Schach" (1917) and "Die Aljechin-Verteidigung" (1922)"

Others: 3 endgame studies with solution by Hans Fahrni are selected on the Website ARVES.org