A quote from Hexameron on him (Hexameron is one of my favorite music history scholars):
"Nicknamed the "Northern Chopin" by Schumann, Adolf von Henselt (1814-1889) was a stellar 19th-century piano virtuoso and composer once as famous as Chopin. In his early virtuoso career, he was respected by many of the early Romantics, and his two sets of etudes received ebullient praise from Schumann, who said they were some of the best piano music being written in the 1830s.
In 1838, Henselt moved to St. Petersburg and was one of the first great pedagogues to teach music in Russia before any conservatories existed. His presence and his compositions arguably established the foundation of the Russian piano school and influenced many Russian composers from Balakirev to Rachmaninov.
Henselt's performing career had a short lifespan. He was notoriously shy and suffered from severe stage fright that eventually terminated his ability to perform in concert. Although his earliest compositions, namely the two sets of etudes and the monumental Piano Concerto in F minor were successful, he composed a relatively small output compared to other pianist-composers of the time. Out of his 45 published works, the two sets of etudes (Op. 2 and 5) must rank as the greatest of their kind, sitting comfortably alongside Chopin's, Liszt's, and Alkan's."