The 1926 Lithuanian coup d'état was a military coup d'état in Lithuania that resulted in the replacement of the democratically elected government with a conservative authoritarian government led by Antanas Smetona. The coup took place on 17 December 1926 and was largely organized by the military; Smetona's role remains the subject of debate. The coup brought the Lithuanian Nationalist Union, the most conservative party at the time, to power. Before 1926, it had been a fairly new and insignificant nationalistic party: in 1926, its membership numbered about 2,000 and it had won only three seats in the parliamentary elections. The Lithuanian Christian Democratic Party, the largest party in the Seimas at the time, collaborated with the military and provided constitutional legitimacy to the coup, but did not accept any major posts in the new government and withdrew in May 1927. After the military handed power over to the civilian government, it ceased playing a direct role in political life.