Thus began a relationship of extraordinary intensity which lasted throughout and beyond Mendelssohn's life (he died in 1847). Moscheles was instrumental in bringing Felix to London for the first time in 1829 – Abraham entrusted Felix to his care for this visit. Moscheles had carefully prepared for it. In London, apart from becoming a regular and successful performer, as well as a musical adviser for the soirées of the Rothschilds, he had become an invaluable aid for Sir George Smart and the Philharmonic Society, advising them of the talents of European musicians he encountered on his own concert-tours. When Smart himself toured Europe in 1825 looking for new music and musicians for the Society, Moscheles furnished Smart with a list of contacts and letters of introduction, including both Beethoven and Mendelssohn. In Prague, Moscheles's brother acted as Smart's guide. Smart visited the Mendelssohns in Berlin and was impressed with both Felix and Fanny. This eventually led to Mendelssohn's invitation to conduct at the Society on his 1829 visit.