Year 1843 (MDCCCXLIII) was a common year starting on Sunday (link will display the full calendar) of the Gregorian Calendar and a common year starting on Friday of the 12-day slower Julian calendar.

Edvard Hagerup Grieg /ˈɛdʋɑɖ ˈhɑːgəɾʉːp gɾiːg/ (15 June 1843 – 4 September 1907) was a Norwegian composer and pianist. He is best known for his Piano Concerto in A minor, for his incidental music to Henrik Ibsen's play Peer Gynt (which includes Morning Mood and In the Hall of the Mountain King), and for his collection of piano miniatures Lyric Pieces.

Edvard Hagerup Grieg was born in Bergen, Norway on 15 June 1843. His parents were Alexander Grieg (1806–1875), a merchant and vice consul in Bergen, and Gesine Judithe Hagerup (1814–1875), a music teacher and daughter of Edvard Hagerup. The family name, originally spelled Greig, has Scottish origins. After the Battle of Culloden in 1746, Grieg's great-grandfather traveled widely, settling in Norway about 1770, and establishing business interests in Bergen.

Edvard Grieg was raised in a musical area. His mother was his first piano teacher and taught him to play at the age of 6. Grieg studied in several schools,^{[clarification needed]} including Tank's School. He often brought in samples of his music to class.^{[citation needed]}

Heinrich Hermann Robert Koch ([ˈkɔx]; 11 December 1843 – 27 May 1910) was a German physician. He became famous for isolating Bacillus anthracis (1877), the Tuberculosis bacillus (1882) and Vibrio cholerae (1883) and for his development of Koch's postulates.

He was awarded the Nobel Prize in Physiology or Medicine in 1905 for his tuberculosis findings. He is considered one of the founders of microbiology, inspiring such major figures as Paul Ehrlich and Gerhard Domagk.

Koch was born in Clausthal in the Harz Mountains, then part of Prussia, as the son of a mining official. He studied medicine under Friedrich Gustav Jakob Henle at the University of Göttingen and graduated in 1866. He then served in the Franco-Prussian War and later became district medical officer in Wollstein (Wolsztyn), Prussian Poland. Working with very limited resources, he became one of the founders of bacteriology, the other major figure being Louis Pasteur.

After Casimir Davaine demonstrated the direct transmission of the anthrax bacillus between cows, Koch studied anthrax more closely. He invented methods to purify the bacillus from blood samples and grow pure cultures. He found that, while it could not survive outside a host for long, anthrax built persisting endospores that could last a long time.