The "War of the Romantics" is a term used by some music historians to describe the schism among prominent musicians in the second half of the 19th century. Musical structure, the limits of chromatic harmony, and program music versus absolute music were the principal areas of contention. The opposing parties crystallized during the 1850s. The most prominent members of the conservative circle were Johannes Brahms, Joseph Joachim, Clara Schumann, and the Leipzig Conservatoire, which had been founded by Felix Mendelssohn. Their opponents, the radical progressives mainly from Weimar, were represented by Franz Liszt and the members of the so-called New German School (German: Neudeutsche Schule), and by Richard Wagner. The controversy was German and Central European in origin; musicians from France, Italy, and Russia were only marginally involved. Composers from both sides looked back on Beethoven as their spiritual and artistic hero; the conservatives seeing him as an unsurpassable peak, the progressives as a new beginning in music. The conservatives Clara Schumann, Joseph Joachim and Johannes Brahms were early key members of a conservative group of musicians. This core of supporters maintained the artistic legacy of Robert Schumann, Clara's husband, who had died in 1856. While Robert Schumann had been a progressive critic and editor of the influential music periodical Neue Zeitschrift für Musik, which he had founded in 1834, he was never a true admirer of Liszt. However, as Schumann maintained exceptionally enthusiastic and artistically fruitful friendships with the emerging vanguard of radical romantics — Liszt in particular — as well as with musical conservatives such as Mendelssohn and Gade, he remained cordial with Liszt at first. He praised Liszt's piano playing in Neue Zeitschrift and reviewed his Leipzig concerts in 1840 favorably. However, as Lisztomania swept through Europe after 1842, both he and Clara believed that Liszt had become self-deluded. After Schumann sold the Neue Zeitschrift to Franz Brendel in 1845, it became an enthusiastic supporter of Liszt and his circle. It also openly played down Mendelssohn and other conservative composers. Though the final break between Liszt and the Schumanns would not come until 1848, the editorial turn that Neue Zeitschrift had taken would color their relations for the rest of their lives. While Liszt remained cordial and at times generous on a professional level toward the Schumanns, they became openly hostile to him. Clara Schumann had long been the more conservative aesthete in the Schumann marriage. She