was Tsar Alexander III of Russia the Uncle of Emperor Wilhelm II of Germany?

1) Alexander III was not the uncle of Wilhelm II (in the strict sense
of the word "uncle"), i.e. Alexander was not the brother of Wilhelm's
father or mother.

Alexander's parents were Alexander II
http://en.wikipedia.org/wiki/Alexander_II_of_Russia
and Maria Alexandrovna of Hesse
http://en.wikipedia.org/wiki/Marie_of_Hesse_and_by_Rhine

whereas Wilhelm's grandparents were -
on the paternal side:
Wilhelm I and Augusta of Saxe-Weimar (parents of Friedrich III)
http://en.wikipedia.org/wiki/Wilhelm_I_of_Germany
http://en.wikipedia.org/wiki/Augusta_of_Saxe-Weimar
http://en.wikipedia.org/wiki/Frederick_III%2C_German_Emperor

and on the maternal side:
Prince Albert and Queen Victoria
http://en.wikipedia.org/wiki/Albert_of_Saxe-Coburg_and_Gotha
http://en.wikipedia.org/wiki/Queen_Victoria

2) However, Alexander III and Wilhelm II were related:
Friedrich Wilhelm III.
http://en.wikipedia.org/wiki/Frederick_William_III_of_Prussia
was the great-grandfather of both Wilhelm II and Alexander III.

Charlotte of Prussia (daughter of Friedrich Wilhelm III)
http://en.wikipedia.org/wiki/Alexandra_Fyodorovna_(Charlotte_of_Prussia)
being the mother of Alexander II, i.e. the grandmother of Alexander III.

3) Furthermore, Wilhelm's cousin Alix of Hesse and by Rhine (granddaughter
of Queen Victoria)
http://en.wikipedia.org/wiki/Alexandra_Fyodorovna_of_Hesse
was the wife of Nicholas II, i.e. daughter-in-law of Alexander III: