Mr Justice Peter Charleton says he wants to conclude the inquiry as quickly as possible and get to the truth.
He has warned that anyone lying is wasting taxpayers' money.
Opening the tribunal with a public statement, Mr Justice Charleton says he has one task, to establish the truth.
And he warned people against lying to the inquiry.
The judge raised questions he will have to answer – can he force the garda commissioner to disclose instructions to her lawyers at the O'Higgins Commission about questioning the motives of Maurice McCabe?
Mr Justice Charleton has called on people who may have information or may be a witness to the tribunal to come forward and submit a written statement to the inquiry within the next fortnight.
After that there will be another opening statement – by lawyers.
And after that full public hearings will get underway – the judge signalling today Garda Superintendent David Taylor will be the main witness, with all eyes too on Commissioner Noirín O'Sullivan.
