Attacking historical ciphers methodology
If you don't know the system, you just check one after the other:


frequency analysis of bigrams detects Ceasar and Playfair. Try Caesar first then Playfair.
Auto correlation method for Vigenere (for each x: count the number of occurances, where letter at position i and i+x are equal. For the correct codeword length, it will spike)
If you have a Hill cipher, you lost.