N v F  EWHC 586 (Fam) dealt with "the vexed question of how the court should, when exercising its powers to award ancillary relief, reflect, if at all, the property that the husband bought to the marriage back in 1993".
The facts: The parties were married in 1993, at which time the husband ("H") had assets worth £2.116m, which equated to £4.2m today. It was agreed that the assets in the case now amount to about £9.714m in value ("This is a not very big money case", said Mr Justice Mostyn).
H did not ask that all of the value of his pre-marital property be reflected in the result, proposing that the wife ("W") should receive £4.17m out of the £9.714m, or 43%. W argued that there should be no departure from equality, on four grounds:
1. That H's pre-marital property had now merged with matrimonial property signifying, in effect, an agreement by H to share it with W;
2. That H had "alienated" certain sums during the marriage;
3. That H had since 2007 eschewed the exploitation of a substantial earning capacity in the financial sector in favour of a lowlier paid job as a schoolmaster; and
4. That H had conducted the litigation unfairly, and had caused unnecessary costs to be incurred.
As a result, the parties were £687,000 apart. "Not very surprisingly," said Mr Justice Mostyn (at paragraph 5), "the combined costs of the parties amount to £652,000. It seems to be an iron law of ancillary relief proceedings that the final difference between the parties is approximately equal to the costs that they have spent."
Held: After reviewing the law, Mr Justice Mostyn concluded (at paragraph 44) "that it would be wrong and unfair for none of H's pre-marital wealth to be excluded from the sharing principle". However, "the marriage was long and the monies were well and truly mingled with marital funds, signifying an acceptance by H that to a great extent the monies, or at least their growth or earnings, would be shared with ... W" (he rejected W's arguments in paragraphs 2-4 above). He concluded from that that £1,000,000 should be excluded from the 'divisible amount' of £9,474,000 (£9,714,000 less £240,000 set aside for the daughter's education), saying that this satisfied the justice of the sharing principle, whilst still just leaving sufficient to meet W's needs.
W therefore received 50% of £8,474,000, or 44.7% of the divisible amount.