Because the Spartans had no written laws or records, it is hard for us to know which of the aspects of their government are attributable to Lycurgus and which are not. Let us discuss some of the major features of their system that are often said to have come from Lycurgus.
The most important feature of this system, at least from our modern perspective, is that it had elements that were democratic, those that were aristocratic, and still others that were monarchical. We can, in a sense trace our divided government back through the Romans to the Greeks and to this Lycurgan system.
The Spartans had kings. Their executive branch was run by two kings. These kings were also their military leaders and their main judges. The Spartans also had an aristocratic body called the gerousia. This was made up of 28 old men. Their main function was to decide what issues were important. They did not decide the outcome of the issues, but only decided which issues would be taken up. The issues would then be taken up by the apella, which was a body made up of all male citizens. This body did not get to debate the issues, but it voted on them. This was, clearly, a form of democracy.
Thus, the most important aspect of the Lycurgan constitution, at least from our point of view, is its combination of democracy, aristocracy, and monarchy.