1.  under (guidance, supervision, rules, the law, etc.)
oft. のもとに or のもとで
2.  under (a flag, the sun, etc.);  beneath
3.  with (e.g. one blow);  on (the promise, condition, assumption, etc. that ...);  in (e.g. the name of)
as ...のもとに
4.  (somebody's) side;  (somebody's) location
usu. written 元