The right for all 18 year olds and older citizens of the UK to vote was won in 1969.
Before this, a variety of caveats and conditions restricted the franchise, keeping out women, the under 21s, and non-property holders for many years.
Of course male freeholders with property worth at least forty shillings have been able to choose their member of Parliament since 1432, so it just depends what your definition of 'democracy' is.
The general election will be held on Thursday 8 June 2017, and you must be registered to vote if you want to take part.
Applications can be filled online in less than five minutes, on the government's website.
If you're not yet registered to vote, the deadline is:
Monday 22 May
If you're already registered to vote, or you'd already met the registration deadline for the local elections that will take place in on 4 May, you will be registered to vote in the general election.
When you register you can also ask for a postal ballot if you think you won't be able to visit a polling station on 8 June.
Who can register?
According to the Electoral Commission, people in England and Wales, anyone aged 17 can register to vote if they will turn 18 before or on 8 June 2017.
Scottish people can register aged 15, but like the rest of the UK must be 18 to vote in a general election.
British, Irish or qualifying Commonwealth citizens, citizens of the Republic of Ireland, or other European Union (EU) member states can also register.
If you successfully registered for the EU referendum and your living circumstances have not changed since then (such as address or right to live in the UK) you will still be able to vote in the general election.
The large number of people who registered in 2016 for the EU referendum created an electorate size of 46,500,001.
On referendum day a whopping 72.2 per cent turned out to vote - much higher than at most elections.
Yet despite having a large franchise, the people voting is unevenly spread.
For instance, figures collected by Ipsos Mori found that in 2010, and 2015, 78 per cent of people aged 65 and over turned out to vote.
By contrast, only 43 per cent of 18-24 year olds took part, which was a decrease of 1 per cent on the previous general election.
In both 2010 and 2015, 68 per cent of white people turned out to vote, but only 56 per cent of all BME persons.
Given the uneven distribution of support for each party within demographics, low turnout in one group can have a significant impact on results.
For instance in 2015, 43 per cent of 18-24 year old voters supported Labour, and 47 per cent of over 65s voted Conservative.
However, this is not to assume that the share of young voters who have not voted, would be certain to vote Labour.
Nor that the smaller proportion of elderly non-voters would also vote Conservative.