Jaan Poska was the mayor of Tallinn during 1913–1917 and was appointed the Minister of Foreign Affairs of Estonia on 24 February 1918; his greatest achievement was participating in 1919, as the leader of the Estonian delegation, in peace talks with Soviet Russia, which led to the signing of the Treaty of Tartu on 2 February 1920. The result of the treaty was lasting peace with Russia, the area behind the Narva river, along with Ivangorod was considered Estonian territory; from the south, Setomaa and highlands located to the east from Ibroska were also given back to Estonia.
Jaan Poska was the man, who after signing the peace treaty, said the following words to the members of the Estonian delegation: “This day is the most important day in the 700-year history of Estonia: today marks the first time that Estonia has been able to make an independent decision about its future."
After signing the peace treaty, Poska continued working as a lawyer and was also involved in preparing the constitution of Estonia.
Jaan Poska street starts at the crossing of the Kollane street and Laulupeo street, extends through Kadriorg and ends at the Narva road. The street was named after Jaan Poska during the First Republic of Estonia, from January 1927 to 30 August 1940, when it was renamed after Aleksander Lainer. The street was renamed back to Jaan Poska street on 18 October 1991.