Populists and euroskeptics increased their seats in Parliament to 25 percent, up from 20 percent five years ago, and are likely to press harder on issues like immigration and the E.U.’s budget. But the populist parties may find it hard to forge alliances.

Analysis: Our correspondent writes that voting was a contest between angry, disaffected nationalists who want to beat back what they see as a remote and overreaching bureaucracy in Brussels, and the once-sleepy, complacent supporters of Europe looking to defend a unity that can no longer be taken for granted.

Limits: The populists were denied the sort of Continentwide earthquake they and their supporters had predicted — and their critics had feared — as turnout jumped in some places to the highest level in 20 years.

Takeaways: In Italy, Matteo Salvini’s anti-immigrant, populist League party came in first, with more than 34 percent of the vote, according to provisional results.

In Germany, the Social Democratic Party did badly, which may prompt it to leave the existing coalition. And in Britain, estimates indicated that the Brexit Party, led by Nigel Farage, was on course to take 31 percent of the vote. Here are more takeaways.