A collection of seldom-viewed paintings by key proponents of the influential Bauhaus art and design school are to be brought together for a rare show in London before going under the hammer at the end of the month.

The exhibition, Bauhaus at 100 Celebrating the Artists and Their Legacy, will run for six days from 20 February at Sotheby’s in London. “It’s a chance to see things that haven’t been seen in public for decades and never in this constellation,” said Thomas Boyd-Bowman, the head of impressionist and modern art evening sales at Sotheby’s. “It’s pretty much the best free show in town.”

The 25 works will showcase the burst of creative energy of the groundbreaking art movement founded 100 years ago in Germany. Its anniversary is being marked with thousands of events across the world, from exhibitions and films to symposia and dance, celebrating the profound way in which it shaped a global artistic vision and is still having an impact today.

Among the highlights will be paintings by Wassily Kandinsky, Paul Klee, Oskar Schlemmer, László Moholy-Nagy and Lyonel Feininger, all of whom were recruited to the Bauhaus faculty by its founder, the architect Walter Gropius.

Bridge II by Lyonel Feininger, a cubist rendition of a gothic bridge. Photograph: Courtesy of Sotheby’s

The most valuable work, due to be auctioned on 26 February, is Kandinsky’s Vertiefte Regung (Deepened Impulse), an oil on canvas from 1928, which it is estimated may raise £7.5m. Painted while Kandinsky was teaching at the Bauhaus in Dessau, it is a meditation on the power of circles, which he considered to be crucial to his works. The painting of colourful spheres seemingly in orbit against a black, cosmic background once hung in the exotic living room of the Dessau Bauhaus quarters he shared with Klee, next to an entirely gilded wall.

Also creating excitement are works by Schlemmer, who is arguably associated more than any other artist with the Bauhaus style. He is credited with continuously reinventing the figurative tradition of western art and his striking painting Tischgesellschaft (Group at Table), depicts figures in perspectival space rendered in geometric shapes, and is considered to be extremely rare.

Its estimated auction price of £1m-1.5m may well be exceeded, owing to the fact that no Schlemmer oil painting has come on to the market for more than 20 years. The expectation is that a new record for a Schlemmer work is likely to be made.

Oskar Schlemmer’s Tischgesellschaft (Group at Table), which has an estimate of £1m-1.5m. Photograph: Courtesy of Sotheby’s

“These Schlemmer works are immensely rare,” Boyd-Bowman said. “Those that exist are almost always in museums, so for a potential buyer it’s very exciting. For those who can’t buy it, coming to the show quite simply it’s a great chance to see a Schlemmer in Britain, which doesn’t happen very often.”

The works displayed together show aspects of the genesis of the Bauhaus – typified in Feininger’s abstract work Bridge II – a cubist rendition of a gothic bridge near Weimar, the city where Bauhaus was born – as well as emphasising how eclectic in their tastes many of the artists were.

“They were like cultural magpies, taking and picking up cues from French avant garde and cubism, as well as emerging from their own movement of German expressionism, into something which is a sort of exciting concoction of all of them,” Boyd-Bowman said.

László Moholy-Nagy’s Segments. Photograph: Courtesy of Sotheby’s

Moholy-Nagy’s Segments is made up of one long rectangular bar and a series of semicircles, creating a rhythm and balance, which, says Boyd-Bowman, “latterly informed a lot of what the Bauhaus design aesthetic is”. Its legacy today, he said, is that “we couldn’t imagine the modern world without it ... their functional aesthetic is something we talk and think about all the time, down to the simple use of primary colours, without even realising it.”

But when the artists – stars of their day – were first appointed to the faculty, it was not as painters, but as pioneers with the job of stripping back all the conventions to build a new aesthetic that rejected the idea of a hierarchy governing what was most important in art. So Klee was put in charge of woodcuts, bookbinding and metalworks, and Kandinsky was tasked with teaching the most basic elements of design.

While the show serves to emphasise the historical lack of interest there has been in German art in the UK, Boyd-Bowman said a shift in attitudes was taking place.

“In the UK we are sadly undernourished in the sense that we have a very poor national collection of German art and that’s something to do with the prejudice of collecting it after the first and second world wars,” he said. “Auctions are often the first chance people get to see these things in the UK.”

A symbiotic relationship between auctions and related shows, such as the recent hit exhibition at the Tate of the Bauhaus textiles designer Anni Albers, or the Barbican gallery’s 2012 show Bauhaus: Art as Life, meant, Boyd-Bowman said: “If you’ve had exhibitions that have revealed an artist or a movement to be so much more exciting and innovative and desirable, there’s a natural desire to seek these works at auction.”

Junger Blaumond (Young Blue-Moon) by Paul Klee. Photograph: Courtesy of Sotheby’s

Most of the paintings for sale are from the collection of the late Dr Erika Pohl-Ströher, a businesswoman and geologist who was the granddaughter of Franz and Marie Ströher, who founded the hair products company Wella in Saxony in 1880.

The Bauhaus movement was based in three German cities – Weimar, Dessau and finally Berlin - from its founding in 1919 until its closure under pressure by the Nazis in 1933. Its members emigrated across the world, spreading its principles from Israel to India.

Tickets for the auction are available by emailing: ImpressionistTickets@sothebys.com