Gda Conor Sheehan was opposing a bail application made on behalf of Peter Collins, 52, of no fixed abode.
He told the court of arresting the defendant shortly before 1am on October 13 in Newbridge.
The defendant faces an allegation of assault on a date unknown between October 11 and October 13 at Main Street, Donnybrook and alleged breach of the Public Order Act at Main Street, Newbridge, on October 13.
After being detained the defendant was cautioned and made no reply the allegations.
Sgt Jim Kelly said the State is seeking a remand in custody because of the possible risk of interference with a witness.
Gda Conor Sheehan said the defendant and the injured party were in a relationship for several years.
He said the woman is in fear and believes the defendant will find her. He added she was told she would be assaulted and she is terrified.
The woman, who was taken to Naas Hospital, was allegedly punched repeatedly and her entire face was black and blue.
Gda Sheehan also said she may have structural damage to her bones and he did not witness the assault.
He said there was visible damage to her face and the injured party was “quite lucky”.
He did not recall seeing worse injuries and he claimed “it was blatantly obvious she suffered a bad beating.”
He said money was allegedly taken from her and her phone was removed. The court also heard that they had been in some form of relationship since 2015.
Gda Sheehan said he believes the defendant will “seek out” the injured party, adding “I believe there is a credible risk this will happen.”
The defendant had provided an address in Dublin but this would not allay his concerns and the defendant also said he would apply for accommodation.
Defending solicitor Brian Larkin said the pair are engaged and the defendant would say he is not responsible for what happened.
Mr Larkin indicated the defendant would abide by strict bail conditions, including residing outside the county and will not come into Kildare.
Judge Desmond Zaidan said the court accepts the defendant is presumed innocent.
He said the objections were sustainable and common sense would indicate the woman is in fear.
He refused bail and remand the defendant in custody until October 20.
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