Supporters of independence for Scotland will launch on Friday what they say is the biggest grassroots campaign in Scottish history, a move that could result in the demise of a 305-year-old union with England and the breakup of Britain. Seeking to tap into a cocktail of historical rivalry, opposing political tastes, and a perception that the British parliament in London does not nurture Scotland's national interests, the "Yes Scotland" campaign says it wants to win a referendum on independence in 2014 and for the country to become fully independent by 2016.