Early attempts to thwart frequency analysis attacks on ciphers involved using *homophonic substitutions*, ie. some letters map to more than one ciphertext symbol.
The earliest known example of this, from 1401, is shown below:

[![Homophonic substitution][1]][1]
[[Source]][2]

One variant is the *nomenclator*, where codewords are used to substitute many common words and names. The example below was used by Mary Queen of Scots in 1586.

[![Mary Queen of Scots Cipher][3]][3]
[[Source]][4]

According to Wikipedia, 

> By the late eighteenth century, when the system was beginning to die
> out, some nomenclators had 50,000 symbols.

What is the best way to go about cracking those kinds of ciphers as the number of symbols used increases?


  [1]: https://i.sstatic.net/OXUek.png
  [2]: http://www.quadibloc.com/crypto/pp010301.htmhttp://www.quadibloc.com/crypto/pp010301.htm
  [3]: https://i.sstatic.net/oEHCp.gif
  [4]: http://www.simonsingh.net/The_Black_Chamber/maryqueenofscots.html