TORONTO -- A dispute among separated spouses over which country their children should live in was correctly settled under a new model formulated by the Supreme Court of Canada, Ontario's top court has found.

In its decision released Friday, the Court of Appeal noted that looking only at where the warring parents had intended to live, as used to be the case, was no longer valid.

"The Supreme Court adopted the hybrid model, which considers both parental intention and the circumstances of the children in determining where the children are habitually resident," the Appeal Court said. "This appeal presents this court with an opportunity to consider and apply the new approach to habitual residence."

The case arose because Nils Ludwig, a German citizen, wanted to take his four children back to Germany, where they had been raised. His estranged wife, Jennifer Ludwig, a Canadian citizen, wanted to stay with them in Canada.

Under the Convention on the Civil Aspects of International Child Abduction -- widely known as the Hague Convention -- determining "habitual residence" determines whether a child has been wrongfully taken to, or kept in, a particular jurisdiction. That left it to the courts to decide whether the Ludwig children, aged 9 to 15, belonged in Ontario or Germany.

Records show the family had lived almost entirely in Germany since the Ludwigs married in 2001. They moved to Canada in August 2017, along with almost all their belongings. They formed plans to run a business, renovated and furnished their new home in Ontario, and otherwise settled in.

The children completed the 2017-2018 school year, made friends, enrolled in various classes, and developed ties with their extended maternal family, according to court documents. Throughout, the parents remained uncertain about how long the family would stay in Canada and whether they would go back to Germany.

The couple split in March last year and Nils Ludwig made plans to leave for Europe. A few months later, his wife said she wanted to stay in Ontario, filed for divorce, and sought custody of the children. He applied under the convention to take the children to Germany. Three of them wanted to stay in Canada; one had no preference.

In January, Superior Court Justice Denise Korpan sided with the mom after concluding the children were habitually resident in Ontario. The dad appealed.

In upholding the ruling, the Appeal Court said Korpan had correctly applied the new hybrid model adopted by the country's highest court last year in a case known as Balev.

Previously, Ontario courts tied a child's habitual residence to that of the parents, which was decided by their "settled intention" to stay in a place for a particular purpose. Under that approach, neither parent could unilaterally change a child's habitual residence without the other's consent. The Balev decision changed that approach.

"The (Supreme Court) adopted a hybrid model that combined parental intention and the circumstances of the children," the Appeal Court said. "The court specifically stressed that the hybrid approach is 'fact-bound, practical, and unencumbered with rigid rules, formulas or presumptions'."

On appeal, Nils Ludwig argued Korpan had applied a child-centric model rather than the hybrid model. The Appeal Court disagreed. Korpan, it said, had specifically compared the children's life in Germany to their life in Ontario and found them essentially similar. She also considered the circumstances of the move to Ontario and found no evidence the parents had decided where they would end up.

"(Korpan) did what Balev required her to do, namely to consider all of the children's relevant links to and circumstances in Ontario," the Appeal Court said.