Eleanora Ehrenbergů (sometimes spelled Eleanora Ehrenbergová or Eleanora Ehrenberg) (1 November 1832 – 30 August 1912) was a Czech operatic soprano.
 In 1854 she made her professional opera debut at the Estates Theatre in the title role of Donizetti's "Lucia di Lammermoor".
 In 1866 she created the role of Mařenka in the world première of Bedřich Smetana's "The Bartered Bride", and in 1868 she portrayed Jitka in the premiere of Smetana's "Dalibor".
 She retired from the stage sometime in the 1880s.
The Bedřich Smetana Museum (Muzeum Bedřicha Smetany) in Prague is a museum which is dedicated to the life and works of famous Czech composer Bedřich Smetana (1824–1884).
 It is situated in the centre of Prague in a small block of buildings right next to Charles Bridge on the right bank of the river Vltava in the Old Town (Novotného lávka 1, 110 00 Praha 1).
Gaetano Rossi (18 May 1774 – 25 January 1855) was an Italian opera librettist for several of the well-known "bel canto"-era composers including Gioachino Rossini, Gaetano Donizetti, and Saverio Mercadante in Italy and Giacomo Meyerbeer in one of his early Italian successes.
 Other composers with whom he worked included Simon Mayr, a composer and Donizetti's teacher, as well as the prolific Giovanni Pacini.
Domenico Gaetano Maria Donizetti (] ; 29 November 1797 – 8 April 1848) was an Italian composer.
 Along with Gioachino Rossini and Vincenzo Bellini, Donizetti was a leading composer of the "bel canto" opera style during the first half of the nineteenth century.
 Donizetti's close association with the bel canto style was undoubtedly an influence on other composers such as Giuseppe Verdi (1813–1901).
The Two Widows () is a two-act Czech opera by Bedřich Smetana based on the libretto of Emanuel Züngel.
 The libretto is based on Jean Pierre Felicien Mallefille's one-act play "Les deux veuves".
 The opera was composed between June 1873 and January 1874, and its premiere took place on 27 March 1874 at the Prague Czech Theatre under the direction of Smetana.
 However, this premiere was not successful and the opera was rewritten in 1874.
 The spoken dialogue was replaced by through-composed recitatives and some of the music and characters were reworked.
 The second premiere on 20 October 1874 was very successful.
 A further revised version was premiered on 17 March 1878, under Adolf Čech.
The Brandenburgers in Bohemia () is a three-act opera, the first by Bedřich Smetana.
 The Czech libretto was written by Karel Sabina, and is based on events from Czech history.
 The work was composed in the years 1862–1863.
 Smetana and Sabina wrote the opera at a time of great Czech patriotism, with the pending opening of a new theatre for production of Czech operas in Prague.
Bedřich Smetana (] ; 2 March 1824 – 12 May 1884) was a Czech composer who pioneered the development of a musical style which became closely identified with his country's aspirations to independent statehood.
 He is thus widely regarded in his homeland as the father of Czech music.
 Internationally he is best known for his opera "The Bartered Bride" and for the symphonic cycle "Má vlast" ("My Homeland"), which portrays the history, legends and landscape of the composer's native land.
Antonín Leopold Dvořák ( ; ] ; 8 September 1841 – 1 May 1904) was a Czech composer.
 After Bedřich Smetana, he was the second Czech composer to achieve worldwide recognition.
 Following Smetana's nationalist example, Dvořák frequently employed aspects, specifically rhythms, of the folk music of Moravia and his native Bohemia.
 Dvořák's own style has been described as "the fullest recreation of a national idiom with that of the symphonic tradition, absorbing folk influences and finding effective ways of using them."
   is a '"festival opera" in three acts, with music by Bedřich Smetana.
 The libretto was originally written in German by Josef Wenzig, and was then translated into Czech by Ervin Špindler.
 In Czech historical myth, Libuše, the title character, prophesied the founding of Prague.
 The opera was composed in 1871–72 for the coronation of Franz Josef as Czech king.
 This did not happen and Smetana saved "Libuše" for the opening of the National Theatre in Prague, which took place nine years later on 11 June 1881.
 After the destruction of the National Theatre in a fire, the same opera opened the reconstructed theatre in 1883.
 The first US performance was reported to have occurred March 1986, in a concert version at Carnegie Hall with Eve Queler and the Opera Orchestra of New York.
Below is a List of compositions by Bedřich Smetana sorted by genre, catalogue numbers, original and English titles.
 JB numbers are from "Tematický katalog skladeb Bedřicha Smetany" (Thematic Catalogue of Works by Bedřich Smetana) by Jiří Berkovec (Prague, 1999).
 B. numbers are from the catalogue by František Bartoš.
 T. numbers are from the 1893 catalogue by Karel Teige.

Question: Out of Italian Gaetano Donizetti or Czech Bedřich Smetana, which opera composer lived and worked earlier?
Answer: Domenico Gaetano Maria Donizetti