Tretyakov started to collect art in 1854 at the age of 22; his first purchase was 10 canvases by Old Dutch masters. He laid down for himself the aim of creating a Russian National Gallery. In his collection Tretyakov included the most valuable and remarkable products, first of all the contemporaries, from 1870 - mainly members of the society of circulating art exhibitions ("Tovarishchestvo peredvizhnyh hudozhestvennyh vystavok" or Peredvizhniki, Передвижники in Russian). He bought paintings at exhibitions and directly from artists' studios, sometimes he bought the whole series: in 1874 he acquired V.V. Vereschagin's "Turkestan series" (13 pictures, 133 figures and 81 studies), in 1880 - his "Indian series" (78 studies). In his collection there were over 80 studies by Alexander Ivanov. In 1885 Tretyakov bought 102 studies by V.D. Polenov painted by the artist during journeys across Turkey, Egypt, Syria and Palestine. He also acquired Vasnetsov’s collection of the sketches made during his work on St Volodymyr's Cathedral in Kiev. Tretyakov had the fullest collection of such artists as: V.G. Perov, I.N. Kramskoi, Ilya Repin, Vasily Surikov, I.I. Levitan, and Valentin Serov. Aspiring to show the beginnings and development of the domestic school of art , Tretyakov began to acquire pictures by masters of the 18th and first half of the 19th centuries and landmarks of Old Russian painting. He also conceived the creation of a "Russian pantheon" - a portrait gallery of famous Russians. He commissioned especially for it portraits of figures of domestic culture from leading masters of this genre - N.N. Ge, Kramskoi, N.V. Nevrev, Perov, Repin.