The party was founded in 1955 by Eric Williams, who took inspiration from Norman Manley's democratic socialist centre-left People's National Party in Jamaica. It won the 1956 General Elections and went on to hold power for an unbroken 30 years. After the death of Williams in 1981, George Chambers led the party. The party was defeated in the 1986 General Elections, losing 33–3 to the National Alliance for Reconstruction (NAR). Under the leadership of Patrick Manning, the party returned to power in 1991 following the 1990 attempted coup by the Jamaat al-Muslimeen, but lost power in 1995 to the United National Congress (UNC). The PNM lost again to the UNC in the 2000 General Elections, but a split in the UNC forced new elections in 2001. These elections resulted in an 18–18 tie between the PNM and the UNC, and President Arthur N. R. Robinson appointed Manning as Prime Minister. Manning was unable to elect a Speaker of the House of Representatives, but won an outright majority in new elections held in 2002 and again in 2007, before losing power in 2010. It returned to power in the 2015 general election under Keith Rowley where it had its best result since the 1981 general election, winning 51.7 percent of the popular vote and 23 of the 41 seats. In the 2020 general election, they won the popular vote and a majority in the House of Representatives, winning 22 seats.