In the period before Britain joined the European Economic Community in 1973 the founding Six set up agricultural and budgetary policies which worked to Britain’s disadvantage and caused friction over a long time. After a lengthy battle to obtain a rebate on contributions to the EU budget, which came to a close with the Fontainebleau Agreement of 1984, the UK contributed to a more liberal, open Europe, especially with regard to the single market and trade and foreign policy. There were sporadic bursts of leadership, as exemplified by Margaret Thatcher's work to complete the single market and Tony Blair's on European security. Britain has been a successful and influential member of the EU, except in a few areas where it has showed reluctance or opted out, most notably treaty change and Economic and Monetary Union. In spite of this, and of the problems that lie ahead in these areas, the balance sheet on both sides is positive.