In the case of Hart v Hart the Court of Appeal made a surprising decision in dismissing Mrs Hart's appeal against a judgment that left her with less than half of the matrimonial assets after a 23 year marriage.
It was Mr Hart's case that he brought considerable wealth to the marriage. Even though he provided the court with insufficient proof of this, he was still awarded more than half of the matrimonial assets. Mrs Hart's award was limited to her needs.
The decision in Hart v Hart provides uncertainty and will no doubt be the cause of more cases proceeding to trial in the hope of convincing the judge that one party should retain more assets than the other party even if they have provided incomplete evidence in support of their case.
If the court follows this decision in the future, it may be worth fully documenting what assets you have/had at the date of your marriage/civil partnership to try to retain these assets upon divorce/dissolution. Although if the matrimonial/civil partnership assets are not enough to meet the needs (e.g. housing) of your spouse or civil partner then your pre-marital assets will need to be taken into account when a final award is made by the court.