I know that I can rename my webapp (or it\'s WAR file) to ROOT but this is a terrible way to do it, IMHO. Now I checked out the tomcat doc & it says
For me both answers worked.
WEB-INF/web.xml
Note: when you declare docBase under context then ignore appBase at Host.
ROOT.war
and place it under webapps. So now unmatched url requests from other wars(contextpaths) will land into this war. This is better way to handle ROOT ("/**") context path. The second option is (double) loading the wars from Webapps folder as well. Also it only needs uncompressed war folder which is a headache.