Cardinal George Pell, the Vatican’s third-highest-ranking official, arrived at a Melbourne court on Monday for the start of several weeks of hearings to determine whether he will face trial on charges of “historical sexual offenses.”

Police officers lined the sidewalk, as a large contingent of the local and international journalists and members of the public watched the cardinal enter the Melbourne Magistrates’ Court.

The slow-moving case — charges were filed in June — will be a test of both Australia’s justice system and the Vatican’s efforts to hold clerics accountable after decades of abuse scandals. Witness testimony began on Monday and is expected to continue for two weeks, during which time the court will be closed to the news media and the public.

Here is a guide to what we know, what we don’t know — and how the case will be shaped by Australia’s court system.