After the 1907 electoral reform, the third Duma, elected in November 1907, was largely made up of members of the upper classes, as radical influences in the Duma had almost entirely been removed. The establishment of the Duma after the 1905 Revolution was to herald significant changes to the previous Russian Imperial autocratic system. Furthermore, the Duma was later to have an important effect on Russian history, as it was one of the contributing factors in the February Revolution of 1917, the first of two that year, which led to the abolition of autocracy in Russia and the overthrow of the Tsar.