The third year of marriage is the happiest one, new research has revealed. A study of 2,000 married adults found a year of post-wedding exhilaration is followed by a year of getting to know each other - but the third year marks the point when couples begin to settle into a comfortable co-existence, having come to terms with each other's imperfections.

It's also around this time that plans to start a family begin, further cementing the relationship.

The in-depth study examined the dynamics of modern married life.

It found that by the third anniversary both parties were content with the financial implications of tying the knot and sharing bills and expenses.

Enjoying the luxury of two salaries also makes this an enjoyable time, along with the fact that renovations or improvements to the marital home are likely to be close to completion.

By contrast, the study found the fifth year is the hardest to overcome due to factors such as tiredness or even exhaustion amid increasing workloads - and children.

Couples find the fifth year of marriage the most difficult

Family lawyer at Slater & Gordon, Amanda McAlister said:

''It's not very often we see clients in those first few years of marriage but by the five year mark or a couple of years after they have children we often have married couples asking us for advice.

''The buzz of the first few years where everything is new is hard to maintain and often people find that married life hasn't lived up to their expectations.

''We encourage anyone having doubts at this point in their marriage to really think about whether it's a crisis that can't be overcome.

''Often those clients will just be having a hard time and six months later their marriage will have completely turned a corner.''

The study also found familiarity with each other, regular bickers over the sharing of chores and the stress caused by financial worries also take their toll.

Bringing a child into the marriage around this point can also put strain on the relationship.

The report also found seven years to be 'the wall', which if scaled successfully paves the way for a long, happy and lasting liaison for matrimony.

Researchers also delved into the emotional and physical toll of trying to make a marriage work.

And they found a reflective one in ten admitted 'they didn't realise how hard it would be', while others confessed to suffering an emotional 'comedown' after the high of the wedding.

One third of people feel there isn't enough affection in their marriage, and one in five say there are days when they regret the decision to get hitched completely.

Unbalanced sex drives, different hobbies or social preferences were found to provide stumbling blocks after the first few years.

The study found half the 2,000 polled said their wedding day was the happiest of their life, and the first year was ranked just behind the third for general happiness.

Major factors behind this were that they were 'basking in the newlywed glow', coupled with unbridled optimism about a new life together.

But that soon faded according to the study, amid the harsh realisation of the determination it requires to make the marriage work - one third feel the love in their marriage has reduced since the big day.

One in ten said they loved their partner less than they did the day they were wed, and around one in five admitted their marriage had not worked out the way they would have liked.

Four out of ten said they could 'do more' to make their marriage work.