Complex sentence: Full power was devolved to the Executive on 2 December 1999, this power was revoked by the Secretary of State on four separate occasions, the first was for a period of 3 months from 11 February 2000--30 May 2000 because of no arms decommissioning.
Split into simpler sentences: Full power was devolved to the Executive on 2 December 1999. The first was for a period of 3 months from 11 February 2000--30 May 2000 because of no arms decommissioning.