What was Wyatt's Rebellion?

I'm back! In early 1554 a rebellion against queen Mary I broke out over fears that her impending marriage to Philip II of Spain would plunge England into becoming nothing more than an extension of Spain. This rebellion has become known as Wyatt’s rebellion, and would end in failure, but what actually was the rebellion, who was involved, how serious was the threat against Queen Mary and why was its biggest casualty Lady Jane Grey, despite her not being remotely involved?