The assassination eventually sparked the Russo-Swedish War of 1741–1743 and also inspired the so-called "Sinclairvisan", a song about Sinclair by Anders Odel.

The Swedish National Portrait Gallery at the Gripsholm Castle in Mariefred includes a painting by Johan Henrik Scheffel of Sinclair wearing uniform and armor from 1728 that is currently deposited in Ulriksdal Palace.

[2] In late 1707 he took part in Charles XII invasion of the Russian heartland where was captured as a prisoner of war after the army's surrender at Perevolochna.

In July 1738 Sinclair, by then the major of the Uppland Regiment and a member of the Secret Committee, undertook a second trip with the aim of trying to arrange a safer way of diplomatic communications between Sweden and the Ottoman Empire.

[3][4] Sinclair's departure went well, he accomplished his mission and at the beginning of April 1739 left Constantinople with letters from the Sultan, the Grand Vizier and the Swedish envoy.

However, on 17 June, near Grüneberg (Zielona Góra), he was overtaken by two Russian officers, captain Kütler and lieutenant Lewitzki, who were dispatched by Münnich with an order to "catch up" the envoy.