WHO IS THE CHOCOLATE KING
The 48-year-old, who is estimated by Forbes magazine to be worth $1.6 billion, started his rise by importing cocoa beans into the Soviet Union in 1991. The project ballooned into the immensely popular candy manufacturer Roshen, the foundation of a business empire that now includes ship-building and one of the country's most influential TV stations.
Unlike many other Ukrainian billionaires, Poroshenko did not make his money in murky post-Soviet privatizations, boosting his reputation as a ''good tycoon.''
WHAT ARE HIS POLITICS
Poroshenko began his political career in 1998 as a lawmaker in a Russia-friendly party and went on in 2001 to help found Party of Regions, the political engine behind ousted president Viktor Yanukovych. But in 2004 he threw his weight behind the Orange Revolution protests that arose after fraud-plagued presidential elections.
He served as head of national security for a few months, but stepped down after months of feuding with the prime minister and allegations of improperly trying to help one of Ukraine's major tycoons. He later returned to serve as foreign minister, and briefly as economics minister after Yanukovych came to power in 2010. He catapulted back into the public eye by allying himself early and openly with the anti-Yanukovych protest movement that broke out in late November 2013.
Supporters regard his moving among factions as a sign of pragmatism amid Ukraine's highly polarized politics. Poroshenko allied with a potential rival, former boxing champion Vitali Klitschko, endorsing him for Kiev mayor as Klitschko endorsed Poroshenko for president.
Poroshenko supports signing an association agreement with the European Union, but has spoken against holding a vote on whether Ukraine should seek NATO membership. He says it's important to mend ties with Russia quickly; relations with Moscow should be equal and should not undermine Ukrainians' desire for closer ties with the European Union, he says.
WHAT WILL HE DO NEXT
Poroshenko faces a growing pro-Russian uprising in the east of the country, where officials say more than 200 people have been killed in clashes between insurgents and Ukrainian forces.
Moments after being sworn in, Poroshenko called on armed groups to lay down their weapons and offered amnesty to ''those who do not have blood on their hands. '' He also promised dialogue with citizens in the east, but not with the insurgents who have declared two regions to be independent ''peoples' republics.''
Ukraine's cash-strapped government, desperate to receive the full $17 billion loan package promised by the International Monetary Fund, will have to undertake serious reforms early in Poroshenko's tenure as president.
Poroshenko also faces a major hurdle in encouraging lawmakers in parliament to agree to hold elections this year instead of in 2017 as scheduled. If he fails, he could face the same challenges as the Orange Revolution government, which took two years to hold parliamentary elections and soon became bogged down by infighting.