  With LOFAR we have been able to image the development of lightning flashes
with meter-scale accuracy and unprecedented detail. We discuss the primary
steps behind our most recent lightning mapping method. To demonstrate the
capabilities of our technique we show and interpret images of the first few
milliseconds of two intra-cloud flashes. In all our flashes the negative
leaders propagate in the charge layer below the main negative charge. Among
several interesting features we show that in about 2~ms after initiation the
Primary Initial Leader triggers the formation of a multitude (more than ten)
negative leaders in a rather confined area of the atmosphere. From these only
one or two continue to propagate after about 30~ms to extend over kilometers
horizontally while another may propagate back to the initiation point. We also
show that normal negative leaders can transition into an initial-leader like
state, potentially in the presence of strong electric fields. In addition, we
show some initial breakdown pulses that occurred during the primary initial
leader, and even during two "secondary" initial leaders that developed out of
stepped leaders.
