# Puzzles/Chess puzzles/Eight Queens

## History

The first known mention of the Eight Queens problems was by writer named Max Bezzel, a German chessplayer in the September 1848 issue of Schachzeitung,a famous chess newspaper.

The problem was proposed again in by Franz Nauck in Illustrirte Zeitung of Leipzig, in the issue of June 1, 1850 . At first, Nauck asserted in the June 29 issue that there are 60 solutions to the main problem. Nauck also included a subproblem, to find all solutions with queens at positions b4 and d5.

In the same year during September, Carl Friedrich Gauss, a German mathematician was aware of the problem upon his reading of the problem in the Illustrirte Zeitung. Gauss remarked that Nauck had declared that there were 60 solutions, but that he found 76 (16 more than the proposer). A few days later, he found that he may make a mistake (4 of his solutions should be removed) leaving 72 solutions. Again, a few days later, he make a crude estimate of possible solutions of between 120 and 168 solutions.

Nauck's correction in the September 21 Illustrirte Zeitung giving 92 as the correct number of solutions

## Problems

The premise for the problems are as followed: Place eight chess queens on an 8x8 chessboard so that none of them lies in the field of attack of any of the others. In other words, no two may lie in the same row, column, or diagonal that are in anyway interferes with one and another.

Here are the queens legal moves illustrated :

## Solutions

There are 92 possible solutions for the eight queens puzzles. But only 12 are considered to be unique solution. The rest of 80 solutions are either inverse, reverse, rotate or mirror images of the solutions

Here are the a few of the solutions as shown: