In 1893 the German Mathematical Society invited Hilbert and Minkowski to write reports on the theory of numbers.
They agreed that Minkowski would cover the more elementary parts of number theory while Hilbert would cover algebraic number theory.
It was reprinted in volume 1 of his collected works, and republished in an English translation in 1998.
Part 2 covers Galois number fields, including in particular Hilbert's theorem 90.
Part 3 covers quadratic number fields, including the theory of genera, and class numbers of quadratic fields.