a Lowercase "d" per here.

The Third Executive (16 May 2011 – 6 May 2016) was, under the terms of the Northern Ireland Act 1998, a power-sharing coalition.

Following the 5 May 2011 elections to the fourth Northern Ireland Assembly the Democratic Unionist Party and Sinn Féin remained the two largest parties in the Assembly.

[2] The Assembly finished selecting an executive on Monday 16 May 2011.