On 29 October 1845, he moved to London, calling himself Julius Josaphat. On 16 November 1845, he converted to Christianity in a ceremony at St. George’s German Lutheran Chapel in London, and changed his name to Paul Julius Reuter. One week later, in the same chapel, he married Ida Maria Elizabeth Clementine Magnus of Berlin, daughter of a German banker.

In 1845, Reuter married Ida Maria Magnus, daughter of Friedrich Martin Magnus, a German banker in Berlin. They had three sons: Herbert, who became the 2nd Baron (succeeded by his son Hubert as 3rd Baron), George and Alfred. Clementine Maria, one of his daughters, married Count Otto Stenbock [sv], and after Stenbock’s death, Sir Herbert Chermside, a governor of Queensland.

A former bank clerk, in 1847 he became a partner in Reuter and Stargardt, a Berlin book-publishing firm. The distribution of radical pamphlets by the firm at the beginning of the 1848 Revolution may have focused official scrutiny on Reuter. Later that year, he left for Paris and worked in Charles-Louis Havas’ news agency, Agence Havas, the future Agence France Presse.

On 17 March 1857, Reuter was naturalised as a British subject. On 7 September 1871, the Duke of Saxe-Coburg and Gotha granted him the noble title of Freiherr (Baron). In November 1891, Queen Victoria granted him (and his subsequent male-line successors) the right to use that German title (listed as “Baron von Reuter”) in Britain.

A telegraph line was under construction between Britain and Europe, and so Reuter moved to London, renting an office near the Stock Exchange. In 1863, he privately erected a telegraph link to Crookhaven, the farthest south-west point of Ireland. On nearing Crookhaven, ships from America threw canisters containing news into the sea. These were retrieved by Reuters and telegraphed directly to London, arriving long before the ships reached Cork.

In 1872, Nasir al-Din Shah, the Shah of Iran, signed an agreement with Reuter, a concession selling him all railroads, canals, most of the mines, all the government’s forests, and all future industries of Iran. George Curzon called it “The most complete and extraordinary surrender of the entire industrial resources of a kingdom into foreign hands that has ever been dreamed of”. The Reuter concession was immediately denounced by all ranks of businessmen, clergy, and nationalists of Persia, and it was quickly forced into cancellation.

Reuter died in 1899 at Villa Reuter in Nice, France. He was buried in West Norwood Cemetery in south London.

The 2nd Baron’s brother George had two sons, Oliver (who became the 4th Baron) and Ronald. The last member of the family, Marguerite, Baroness de Reuter, widow of the 4th Baron and Paul Julius Reuter’s granddaughter-in-law, died on 25 January 2009, at the age of 96.