Excerpts from Books and Wikipedia
"The offensive involved a major Russian attack against the armies of the Central Powers on the Eastern Front. Launched on 4 June 1916, it lasted until late September. It took place in an area of present-day western Ukraine, in the general vicinity of the towns of Lviv, Kovel, and Lutsk. The offensive takes its name after the commander in charge of the Southwestern Front of the Imperial Russian Army, General Aleksei Brusilov." [Wikipedia] "The last major Russian offensive of World War I, the Brusilov offensive led to the major weakening and ultimate downfall of both the Russian and Austrian monarchies. . . . The Brusilov offensive did not cause the revolution, but the losses suffered in the offensive . . . Meant that the cost of the greatest Russian success was actually the final contribution. . . . Austrian weakness from that point spelled the doom of the Hapsburg monarchy in Vienna [dismantling of the Hapsburg Empire in 1919 at Versailles]. The last of the continental European empires, Austria-Hungary was comprised of a polyglot population held together by nothing but force. Without a strong military to keep the population quiet, ethnic tensions that had seethed for decades boiled more fiercely . . ."