Even though he was just a 14-year-old Scandinavian German who had never even been to Sweden, he was very popular among the peasantry, in Finland especially for the fact that he was also the nephew of Empress Elizabeth of Russia and could thus ensure a more enduring peace.

It has been described of Charles Peter of Gottorp that he identified himself with his Swedish heritage and that even afterwards, living in St. Petersburg, would have liked to make his own environment and lands to resemble Scandinavia.

When the Russian counter-offensive started in March 1742, Chancellor Bestuzhev probably toyed with the idea of making a buffer state in between Sweden and Russia.

By July 1742, Russia had occupied all of Finland, meeting almost no resistance[1] at all due to ineffective Swedish military command and forces, and that month a group of Finnish peasants pleaded with the Russians to make the duke the King of Sweden.

Known representatives that showed up in the city were e.g. freiherrs i.e. barons Henrik Rehbinder and Johannes Gripenberg, vicars pastors from Loimaa, Halikko, Pöytyä and Maaria and mayors of Rauma and Pori.

Encouraged by Russians' earlier promises of independence, friendly occupation and their own apparent willingness to seize the moment, Finns presented the general with the decision to ask Duke Peter of Holstein-Gottorp to be the King of Finland.

At the same time, the riksdag of Sweden had gathered in Stockholm, trying to find a way out of the military and political situation generated by the Hats' hasty and ill-advised war.

New negotiations were thus opened, and Elizabeth agreed to restore the greater part of Finland if her cousin, Adolph Frederick of Holstein, was elected successor to the Swedish crown, thus concluding the war by the Treaty of Åbo Turku on 7 August 1743.

In late 1742, general Keith was succeeded in the leadership of civil administration of Finland (based at Turku) by the new Governor-General, Johannes Balthasar von Campenhausen.

Häkkinen and Sippu (pages 84–85) mention that still in the 1790s, certain farmers of the villages of Liikkala, Mämmälä and Ruotila in Old Finland, lodged a claim in court where they pleaded certain provisions of the 1742 Manifest of Empress Elisabeth among other points of law to support their position in that lawsuit.