Furshtatskaya Street runs from Liteyny Prospect to Potemkinskaya Street. The earliest recorded name of the passage—4th Line from the Neva River—was documented on maps from the 1720s. Later, the street appeared as the 3rd Artillery Line, 3rd Line of the Artillery Settlement, and from 1751 as the 3rd Pushkarskaya Street. The last three names are connected to the nearby Foundry Yard. The craftsmen and artillerymen working there were called pushkars (gunners).

Before the layout of Tauride Garden in 1783, the street extended a bit further and ended at the Samoroyka River, which flowed from the Ligovsky Basin (at the beginning of the modern Ligovsky Prospect) and emptied into the Neva. The street received its current name, Furshtatskaya Street, in 1780. This name is linked to the fact that on the site of the current house No. 21 and its inner courtyard was the Furshtatsky Yard of the Life Guards Preobrazhensky Regiment (the courtyard building has been preserved). The word "furshtat" is of German origin. It means a forage train. However, initially, this word was not entirely clear. Therefore, on maps from the turn of the 18th–19th centuries, an incorrect spelling "Forshtatskaya" appears, derived from the word "forshtat" meaning "suburb." In the mid-19th century, the most popular erroneous variant of the name—Furshtadtskaya—became widespread. This mistake was due to the fact that streets named after cities like Kronstadt and Jakobstadt appeared in Petersburg, with the compound part "stadt" meaning "city." On May 19, 1923, Furshtatskaya was renamed to Petra Lavrova Street, in honor of the centenary of the birth of the theorist of populism, prominent philosopher, and publicist Petr Lavrovich Lavrov (real surname – Mirtov, 1823–1900), who lived there.

Petr Lavrov, an artillery colonel who taught mathematics at military educational institutions in Petersburg, began collaborating with Herzen’s "Kolokol" and other foreign publications in 1857, and in 1862 defended arrested students. Lavrov’s activities provoked the authorities’ displeasure, and after the failed assassination attempt on Alexander II by D. Karakozov in 1866, Petr Lavrov was exiled to Siberia. Four years later, he escaped from exile, settled in Europe, met Marx, joined the First International, and began his journalistic work.

On October 4, 1991, the street’s historical name was restored.

Sources:

https://toponimika.spb.ru/peterburg-v-nazvaniyakh/item/385-furshtatskaya-ulitsa.html