EuroBasket
I see your also a fan on the EuroBasket, In fact the first championships for the eurobasket were held three years after the establishment of FIBA way back in 1935.
Who played?
Well Switzerland was chosen as country to host the game, and after that ten other countries joined as far as I know. 
Which ten?
I'm not really sure sorry, But I love to see how your a huge fan. 
I just want to go play there myself
Well you cant play anymore because only one match was played and that was between Portugal and Spain.
Oh that's a shame
In the end the final game would then see Latvia as the grand champions.