  We formulate a new equivariant Main Conjecture in Iwasawa theory of number
fields and study its properties. This is done for arbitrary one-dimensional
$p$-adic Lie extensions $L_\infty/K$ containing the cyclotomic
$\mathbb{Z}_p$-extension $K_\infty$ of the base field. As opposed to existing
conjectures in the area, no requirement that $L_\infty/K$ be abelian or that
$L_\infty$ be totally real is imposed. We prove the independence of the Main
Conjecture of essentially all of its parameters and explore its functorial
behaviour. It is furthermore shown that, to a large extent, this new conjecture
generalises existing ones of Burns, Kurihara and Sano and Ritter and Weiss,
which enables us to deduce its validity in several cases.
