What is "spearheaded"

Usage examples of "spearheaded".

But during the last couple of decades theoretical progress spearheaded by the late Irish physicist John Bell and the experimental results of Alain Aspect and his collaborators have shown convincingly that Einstein was wrong.

William Wilberforce, in a campaign forged with his lifelong friend William Pitt, spearheaded a movement that resulted, in 1807, in the abolition of the slave trade in the British empire.