Boris Kollar, 51, Slovakia

Image Boris Kollar Credit... Sme Rodina

Mr. Kollar, a wealthy businessman, formed his own political party last year — Sme Rodina, or “We Are Family” — and shocked the Slovak establishment by earning 11 seats in the country’s 150-seat National Council on a platform of libertarian economics, Euro-skepticism and fierce opposition to more immigration. His slogan: “Trust me, I’m not a politician.” A well-known tabloid figure and media celebrity, Mr. Kollar has 10 children from nine different mothers.

Bogoljub Karic, 63, Serbia

Image Bogoljub Karic Credit... Marko Djurica/Reuters

Mr. Karic, along with three brothers and a sister, built a family business empire that has expanded to telecommunications, construction, finance, media and international trade. He also started the private BK University. But his initial foray into politics ended with his fleeing into exile in 2006, under investigation by Serbia’s chief organized crime prosecutor, which he characterized as politically motivated. Mr. Karic returned to Serbia on Dec. 30, just days after the prosecutor ended the investigation without charges. Mr. Karic denies he will run for president in the coming elections, but notes that his party, the Strength of Serbia Movement, recruited 60,000 new members since his return from exile.

Aivars Lembergs, 63, Latvia

Image Aivars Lembergs Credit... Ilmars Znotins/Agence France-Presse — Getty Images

The extent of Mr. Lembergs’s wealth, and its source, are fairly vague, but he has used his business and political acumen to remain the mayor and chief political force in the seaport of Ventspils, an office he has held since 1988, the year before communism fell. Flamboyant, outspoken and a familiar figure in Latvian media, Mr. Lembergs made his fortune in the tumultuous years after the transition to capitalism. His politics are populist. He refers to NATO as “an occupying force.” And he remains the leading figure in a coalition between his party and the Union of Greens and Farmers, a strange-bedfellows conglomeration of environmental activists and conservative farm groups. He has faced repeated charges of corruption, money laundering, bribery and abuse of office.