For a state with no written constitution the UK has a relatively robust polity which, with the exception of a few crises, such as the Cromwellian Republic and Irish secession, has been remarkably resilient compared with many of its major European neighbours. For sure, there have been periods when elements of the constitution, such as the Monarchy or the House of Lords have come under threat, but, until recently, the political system and constitutional machinery have remained largely intact in a relatively successful, though extremely anachronistic mode of governance. The very conservative nature of the UK polity is reflected in the largely bipartisan nature of the political party system and the undemocratic and deferential nature of the Monarchy and upper chamber. That said, there have been a number of changes in the political and constitutional structures and systems that are worthy of brief consideration. Thus, this chapter looks at changes that have allowed the development of the democratic system through extension of the franchise, the increase of the power of the House of Commons over the House of Lords and the Monarchy, the increase in the power of the Prime Minister and Cabinet over the Commons and the developments that made the UK one of the most centralised states in the developed world. We also consider the development of the current party system, the geographical devolution of power and finally some of the wider political issues that have affected the UK in recent years.