Who is Theodore Heckel from Bonhoeffer: Pastor, Martyr, Prophet, Spy and what is their importance?

Heckel was the head of the German church outside of Germany in the years before and during the war. It was on his invitation that Bonhoeffer first traveled to England, where he met George Bell (see below) and solidified his conservative theological and liberal political beliefs. As Bonhoeffer became more and more involved in the anti-Nazi movement, Heckel became more and more resentful and rejecting of him. Heckel eventually became the bishop of the Reich Church (see "Objects/Places"), and a bitter opponent of Bonhoeffer personally, politically, and theologically.