Conservative–DUP agreement
The Conservative–DUP agreement was a confidence and supply agreement between the Conservative Party and the Democratic Unionist Party (DUP) following the 2017 general election which resulted in a hung parliament. Negotiations between the two parties began on 9 June 2017, the day after the election, and the final agreement was signed and published on 26 June 2017.
Source: Wikipedia — Conservative–DUP agreement (CC BY-SA 4.0)