Born into the family of painter Charles Beggrow. He studied at the Engineering and artillery school of the Navy Department. In 1863 the officers took the oath and enlisted in the Navy. Accompanied Grand Duke Alexei Alexandrovich in the circumnavigation in 1871−1872 1873 G. A. Jensen entered the Academy of fine Arts and began teaching at the landscape class of Professor M. Klodt. In 1874, retires and goes to Paris. In 1875, in connection with the death of his father, returned to Russia. In 1899 was awarded by the Council of the Academy of Arts the title of academician. In 1892 he settled at Gatchina. Since 1906 he continuously lives in Gatchina. The last half year of life due to serious illness was forced to abandon painting. In the night from 14 to 15 April 1914 A. Jensen, exhausted by illness, he committed suicide with a shot to the heart.
The son of artist K. P. Beggrow. Painter and watercolorist. Many of his works devoted to the sea theme — types of port-cities, famous ships ("Neva Embankment", 1876; "Le Havre", 1876; "View of St. Petersburg", 1882; "the Interior of the battleship "Chesma"", 1902; "Venice", 1906, etc.).
Inherited from his father artistic ability, A. K. Beggrov, however, became a naval officer. Only in 1870, it is an adult, he began attending the St. Petersburg Academy of Arts as an auditor at the workshop of M. K. Klodt.
In 1871 — 74. education continued in Paris under J.-F. Bonn and A. Bogolyubov. In France his favorite motifs were the coastal areas of Tréport, Le Havre, Concaro. Sea for long captures the imagination of the artist, was confirmed as the main theme of creativity.
However, in his early works or not yet fully independent. At this time Jensen is influenced by the popular French seascape by E. Isabey. 15 1873 in OH for exposed work "Kind of fool name is kanei on the island of Condie", "Imperial yacht "Derzhava"", "Steamer "Grand Duke Constantine"" A. Jensen was awarded a small silver medal.
Since 1874 he participated in exhibitions TPHV, and in 1876 he became a full member of the Association. In A. Beggrova in 1870−80-s. there is an interest to revive the landscape shapes people staffage. Along with sea views, he writes, are now increasingly urban. VII shown in a traveling exhibition painting "Neva Embankment" (1876) marked the beginning of the cycle Petersburg landscape artist. A. Jensen wrote not only oil paints, he willingly worked with watercolors.
In 1885, the artist was one of the founders of the "Society of Russian watercolors." Watercolor made many views of St. Petersburg, Venice, Normandy. As a naval officer and painter of the Navy Department, Beggrov participated in several round-the-world expeditions. In 1899 the St. Petersburg Academy of arts honors him the title of academician of painting, and in 1912 he was its honorary member. During his life he enjoyed great fame. His works were reproduced in popular magazines like "field", "North", "world illustration".