The 72-year-old man, who cannot be named for legal reasons, has pleaded guilty to 17 counts of indecently assaulting 11 boys during the 1970s and 1980s.

The Supreme Court in Hobart heard that he assaulted each boy in strikingly similar ways, following a pattern of abuse that  spanned many years.

Many of the boys were assaulted inside the principal’s office or  the school’s storage sheds, or during car trips.

The court heard that he would sit each victim on his lap, asking them questions such as ‘‘do you want to be a good child?’’ and ‘‘does that tickle?’’

One   boy who was assaulted six separate times told his parents of the abuse, and they   took the claims to police.

The North-West man was interviewed in 1983 and admitted showing boys attention and affection, but denied any sinister motives.

No court action was taken, but the Education Department launched an independent investigation.

The man admitted to nursing, kissing and cuddling his students, as well as taking photos of a group of naked boys inside a swimming pool changing room.

The department considered his position untenable, and he was relocated to another school.

Allegations against him resurfaced last year as a result of a Royal Commission into Institutional Responses to Child Sexual Abuse, and police pressed charges.

Three of his victims on Wednesday delivered harrowing victim impact statements.

One victim said the abuse had irrevocably changed his life, pushing him to self-medicate with drugs and alcohol.

The victim soon pushed himself to the very edges of society, becoming locked in a spiral of risky and destructive behaviour.

‘‘As long as it didn’t hurt anybody else, I didn’t care if I lived or died,’’ the victim said.

The court heard it was not until the victim hit rock bottom and landed in prison that he turned his life around.

‘‘Yes, I am still a victim, but I refuse to let that disgusting episode ruin the rest of my life,’’ he said.

The former student said he would live with never-ending pain  but vowed never to forgive or forget the ‘‘evil, conniving and pathetic excuse for a human being’’ who had ruined so many lives.

Two more victims also spoke of how the abuse had destroyed their trust in others, damaged relationships and left them feeling deep shame, disgust  and guilt.

The 72-year-old man has also been charged with molesting three of his stepchildren.

He will remain in custody before returning to court on July 20.