Complex sentence: Maison Louis Jadot was founded by Louis Henry Denis Jadot in 1859, but the Jadot family had bought a well-known Beaune vineyard, Clos de Ursules, already in 1826.
Split into simpler sentences: Maison Louis Jadot was founded by Louis Henry Denis Jadot in 1859. The first vineyard bought by the Jadot family is the well-known Beaune vineyard, Beaune Clos des Ursules, already in 1826.