Brighton Secondary College principal Richard Minack on Friday appeared as a witness at a Federal Court trial brought by five former students against him, the school, teachers and the state of Victoria.
The students allege they experienced anti-Semitic bullying, discrimination and negligence at the school between 2013 and 2020, which has been denied by all respondents.
Mr Minack told the court he wanted to make a "powerful instructive speech" for the anniversary of the 2019 Christchurch mass shootings, when he gave a speech that offended students.
He said he wanted students to think about "how these things might possibly come out and make them vigilant to these processes".
"I wanted to make a speech that was really authentic and powerful," he said.
"So I decided to share some of my own personal family history with the school, which I had not done before."
In the speech Mr Minack discussed how his father had fought for the German army during World War II and used the N-word.
Asked about why he did this, he said a Brighton school alumni had told him the school's uniform in the 1950s had the colours of "Nigger brown" and "Chinaman yellow".
"That put the idea of colour in my mind, it's such a ubiquitous thing," he said.
"I took those two elements and constructed the speech."
The speech attracted negative media attention after recordings were leaked on social media.
Mr Minack said students spoke to him after the speech and told him they were offended by his use of the N-word, so he decided to apologise.
"I had offended some students and I thought it was the right thing to do to apologise for any offence that I may have caused them."
He said some staff and parents congratulated him for the speech, after he decided to distribute a transcript to the wider school community.
Mr Minack told the court on Thursday the speech led to an increase in graffitied slurs against Black people around the school.
His evidence before the trial will continue next week.
