Sergey Semyonovich Urusov (August 3, 1827 – November 20, 1897) was a leading 19th century Russian player and self-published amateur mathematician. His brother Dmitry Urusov (1829-1903) was also a strong player. Urusov was a member of the Russian nobility, holding the title of Prince and an officer in the Tsarist army. In 1853 he played a few games against Alexander Petrov who was visiting Saint Petersburg; the score is usually given as 3–1 in favor of Petrov though sources vary. The same year he won a match against Ilya Shumov by 4–3, and again in 1854 by a score of 12–9. Also in 1854, he drew a match against Carl Jaenisch by a score of 2-2.
As an Army officer he fought in the Crimean War in 1854–55 and was awarded the Order of Saint George for bravery during the Siege of Sevastopol. During the war he met Leo Tolstoy and the two became friends. They later fell out after Tolstoy left the Russian Orthodox Church.
Following the Crimean War, he left the army and devoted himself to chess. There were few organized tournaments at the time, so his chess activity consisted primarily of individual matches. He was considered the second strongest Russian player after Petrov, who beat him again in 1859 by a score of +13 −7 =1; the same year he won matches against Shumov and Viktor Mikhailov. He drew a match against the Austrian Ignatz Kolisch in 1862, who was one of the strongest players in the world at the time, and defeated the strong German player Philipp Hirschfeld in 1866. In 1878 he retired from chess and bequeathed his collection of chess books to Ilya Tolstoy.
The Urusov Gambit in the Bishop's Opening (1.e4 e5 2.Bc4 Nf6 3.d4) is named after Sergey S. Urusov. You don't see this gambit very often these days, but in the last 4 years or so I have played it in correspondence game nine times and scored +5 -0 =4 with it. White's compensation is mainly piece activity and open lines, so white must play very actively and precisely to force a concession before black can catch up on development. Some good analysis on the gambit can be found HERE. In all my analysis I relied heavily on analysis by Michael Goeller found in this link.
Also, in the games that were played a few years ago I also used several different engines as well as Rybka's Monte Carlo analysis. In Monte Carlo analysis you start with a position and then Rybka plays hundreds, or perhaps thousands, of games against itself at lightening speed in order to give a rough idea of the results. I have of necessity had to trim out literally reams of analysis on the opening in the attached game, but engine analysis seems to indicate that the Urusov Gambit is much better than its reputation. A lot of the notes on the opening of this game came from Goeller's site as well as several engines that were available at the time the game was played.