Early liberalism in a sense led to the throwing off of the chains of feudalism to establish rights that were due to each human. Natural rights theory was supported by intellectuals such as John Locke and Jean Jacques Rousseau. They highlighted a few important things:

Citizens have particular inalienable rights (life, liberty and property)
These rights need to be protected by the state; for Locke this was an important aspect of the social contract
The government is not allowed to interfere with people's rights, unless there is a valid reason to do so
If the government infringes on the rights of people, then the people have the right to dissolve the government
People are the ones that give permission to the government before it can exercise power
This is central to the idea of liberal democracy
Early liberalism sought to maximise the actions of the individual by not constraining them
Moreover, this relies often on minimal state approach and a belief in the power of market economics