Why do statves have 'v' instead of 'u'?

Evolution of the Roman alphabet.

The Latin, or Roman, alphabet was created in the 7th century BC (more precisely 753 BC), according to legend. It was based on the Etruscan alphabet, which was derived from the Greek. Of the original twenty-six Etruscan letters the Romans adopted twenty-one.

The original Latin alphabet was A, B, C (which stood for both g and k), D, E, F, I (the Greek zeta), H, I (which stood for both i and j), K, L, M, N, O, P, Q, R (though for a long time this was written P), S, T, V (which stood for u, v, and w), and X. Later the Greek zeta (I) was dropped and a new letter G was placed in its position.

After the conquest of Greece in the first century BC the letters Y and Z were adopted from the Greek alphabet and placed at the end. Now the new Latin alphabet contained twenty-three letters.

It was not until the Middle Ages that the letter J (to distinguish it from I) and the letters U and W (to distinguish them from V) were added.

So 'V' is a middle aged letter. ;-)