Ensuing generations of Grotrian family members led the company to become one of the finest piano manufacturers in Germany.

Grotrian-Steinweg pianos were preferred by some famous pianists, and they received accolades at the World's Columbian Exposition in Chicago.

Grotrian-Steinweg operated an orchestra and a concert hall, and established sales rooms in a half dozen major cities in Germany, and by 1920, in London as well.

Economic depression in the 1930s and war in the 1940s caused Grotrian-Steinweg to decline severely and then lose its factory completely.

In the 1950s, an annual piano-playing competition was founded by the company, to identify promising young piano students.

Steinway & Sons sued to prevent them from using the Steinweg name, resulting in a 1975 decision by the United States Court of Appeals for the Second Circuit.

[3] In Germany, Heinrich Engelhard Steinweg (1797–1871) started making pianos in 1835 from his house in Seesen at the edge of the Harz mountains;[4] a source of fine beech and spruce wood for the instruments.

[2] In 1854, Friedrich Grotrian received the Müller-Mühlenbein pharmacy as an inheritance from an uncle, so he moved back to Germany to manage it.

Theodor Steinweg and Grotrian moved the piano factory to Braunschweig, setting up shop in a former mayor's mansion at 48 Bohlweg Street in the inner, medieval part of the city.

Theodor Steinweg was needed by his family in New York to help manage Steinway & Sons after his brothers Henry and Charles died.

Their father Wilhelm Grotrian Sr took Willi with him to Chicago in 1893; there, at the World's Columbian Exposition, Grotrian-Steinweg won an award for fine quality.

[11] Pianists Eugen d'Albert, Ignacy Jan Paderewski and Clara Schumann expressed a preference for Grotrian-Steinweg pianos.

[11] Grotrian-Steinweg was counted among the top German piano manufacturers along with Bechstein, Blüthner, Feurich, Ibach, Lipp and the Hamburg division of Steinway.

"[14] Willi Grotrian methodically set about to improve the systems and standards the Grotrian-Steinweg company used to produce pianos.

[15] The Grotrian-Steinweg brand was well known for being of the highest quality: the company was named purveyor to some 30 "Kaisers, Kings and royal houses".

[2] Willi Grotrian, his son, led the company but it was greatly reduced in manpower and orders for pianos.

After the war, the company resumed as before, expanding sales in 1920 by establishing a London shop under the brand name Grotrian-Steinweg.

This number dropped significantly in the 1930s during the Great Depression; fewer than 500 pianos were made in 1931, and the workforce was reduced to less than 200.

In World War II, the Grotrian-Steinweg factory (like many others in Germany) was ordered to switch to fabricating parts for aircraft.

[14] By 1948, production had resumed; composer and pianist Wilhelm Kempff went on record as an admirer of the "sonority and exquisite execution" of the post-war work.

The competition took place in the Braunschweig location of the Hertie department store, with audience applause used as the gauge to determine the winner.

In 1975, the United States Court of Appeals for the Second Circuit heard the arguments in Grotrian, Helfferich, Schulz, Th.

Steinway & Sons, defendant, counterclaimed that their brand, well known and strongly positive in the US, was weakened by consumers' confusion as to whether the pianos were related.

"[23][24] The court felt that Grotrian-Steinweg—a brand not very well known in the US—was unfairly given an extra measure of credibility based on the strong reputation that Steinway & Sons had built.

"[26] The English-language section of Grotrian's website does not have any reference to the surname "Steinweg", unlike the French-, German- and Russian-language versions.

[14] In 1999, Knut Grotrian-Steinweg stepped down from active supervision of the company, and put day-to-day control in the hands of Burkhard Stein, an industrial manager and piano builder.

[2] In 2015, a majority interest in Grotrian-Steinweg was purchased by Parsons Music Group, a company based in Hong Kong.

[30] In 2010, the company issued a special 175-year anniversary model, a 46.5-inch (118 cm) upright called Composé Exclusif, of which 50 were produced.