The document proposed a number of groups based on Artemis that would be autonomous, consisting of about 1500 personnel and deployable within 15 days. These would be principally in response to UN requests at short notice and can be rapidly tailored to specific missions. They would concentrate on bridging operations, preparing the group before a larger force relieved them, for example UN or regional peacekeepers under UN mandate. The plan was approved by all groups in 2004 and in November that year the first thirteen Battlegroups were pledged with associated niche capabilities. Early development (2005–2015) From 1 January 2005 the Battlegroups reached initial operational capacity; full operational capacity was reached on 1 January 2007. Although EU member states were initially highly motivated to volunteer to fill up the roster, the fact that participating member states have to cover their own costs, which especially burdened the smaller states, has made them more reluctant. Besides, many EU member states had simultaneous obligations to fulfill for ISAF and the NATO Response Force, amongst others. This combined with the fact that EU Battlegroups have never been deployed (due to slow political decision-making), despite several occasions in which they according to various experts could or should have been (most notably DR Congo in 2006 and 2008 and Libya in 2011), has led to increasing gaps in the standby roster. Joint funding and actual usage may resolve these issues. MPCC, EDF and PESCO (2016–2020) On 23 June 2016, the Brexit Referendum resulted in a vote in favour of the United Kingdom leaving the European Union. Since the UK and France were the largest military powers within the EU, this would mean a serious reduction in forces available for common European defence. On 28 June, High Representative Federica Mogherini presented a new plan, the Global EU Strategy on Security and Foreign Policy, for rigorous further European military integration between the EU member states. These included more cooperation when planning missions, training and exercising soldiers, and the development of a European defence industry. For the EU Battlegroups specifically, the plan aims to remove the obstacles preventing their rapid deployment, such as the lack of a European military headquarters. Although stressing that NATO will remain the most important defence organisation for many EU countries, Mogherini stated that the Union should be able to operate 'autonomously if necessary' on security matters. Referring to the EU's diplomacy and development record, she