"to secure the prompt return of children wrongfully removed to or retained in any Contracting State."
"The removal or the retention of a child is to be considered wrongful where – (a) it is in breach of rights of custody attributed to a person, an institution or any other body, either jointly or alone, or under the law of the State in which the child was habitually resident immediately before the removal or retention; and (b) at the time of removal or retention those rights were actually exercised, either jointly or alone, or would have been so exercised but for the removal or retention. "
"Where a child has been wrongfully removed or retained in terms of Article 3 and, at the date of the commencement of the proceedings before the judicial or administrative authority of the Contracting State where the child is, a period of less than one year has elapsed from the date of the wrongful removal or retention, the authority concerned shall order the return of the child forthwith."
"Notwithstanding the provisions of the preceding Article, the judicial or administrative authority of the requested State is not bound to order the return of the child if the person, institution or other body which opposes its return establishes that – (a) the person institution or other body having the care of the person of the child was not actually exercising the custody rights at the time of removal or retention, or had consented to or subsequently acquiesced in the removal or retention; or (b) there is a grave risk that his or her return would expose the child to physical or psychological harm or otherwise place the child in an intolerable situation."
"A court cannot refuse to return a child on the basis of Article 13(b) of the 1980 Hague Convention if it is established that adequate arrangements have been made to secure the protection of the child after his or her return."
“[45]. The law in respect of the defence of harm or intolerability under Art 13(b) was examined and clarified by the Supreme Court in Re E (Children)(Abduction: Custody Appeal)[2011] 2 FLR 758 . The applicable principles may be summarised as follows: i) There is no need for Art 13(b) to be narrowly construed. By its very terms it is of restricted application. The words of Art 13 are quite plain and need no further elaboration or gloss. ii) The burden lies on the person (or institution or other body) opposing return. It is for them to produce evidence to substantiate one of the exceptions. The standard of proof is the ordinary balance of probabilities but in evaluating the evidence the court will be mindful of the limitations involved in the summary nature of the Convention process. iii) The risk to the child must be ‘grave’. It is not enough for the risk to be ‘real’. It must have reached such a level of seriousness that it can be characterised as ‘grave’. Although ‘grave’ characterises the risk rather than the harm, there is in ordinary language a link between the two. iv) The words ‘physical or psychological harm’ are not qualified but do gain colour from the alternative ‘or otherwise’ placed ‘in an intolerable situation’. ‘Intolerable’ is a strong word, but when applied to a child must mean ‘a situation which this particular child in these particular circumstances should not be expected to tolerate’. v) Art 13(b) looks to the future: the situation as it would be if the child were returned forthwith to his or her home country. The situation which the child will face on return depends crucially on the protective measures which can be put in place to ensure that the child will not be called upon to face an intolerable situation when he or she gets home (where, as in this case, Art 11(4) of BIIa applies, the court cannot refuse to return a child on the basis of Art 13(b) of the Convention if it is established that adequate arrangements have been made to secure the protection of the child after his or her return). Where the risk is serious enough the court will be concerned not only with the child's immediate future because the need for protection may persist. …”