It was a day of drama for Peru, which saw her predecessor arrested for alleged rebellion and impeached.
In less than five years, Boluarte became Peru's sixth president when he was elected to the top job at Congress.
As part of the ceremony, 101 members of the 130-member legislative body voted in favor of impeaching former leader Pedro Castillo by a majority of 101 votes.
As the tumultuous day began, it was announced by the then-president Castillo that the Congress was going to be dissolved and an emergency government would be installed.
In addition, he called for the holding of parliamentary elections as part of the process of writing a new constitution.
As a result of the move, a number of cabinet members resigned, there was a backlash from top officials, and his neighbors condemned him - and he was ultimately impeached by Congress.
US Ambassador in Peru Lisa Kenna tweeted that Castillo should "reverse" his decision and allow Peru's democratic institutions to operate as they should.
Any act that undermines Peru's democracy or contradicts its constitution will be categorically rejected by the US State Department,” said spokesperson Ned Price.
Following Castillo's impeachment in Congress, police detained him in Lima's capital city.