referendum known as ‘Brexit’.

The decision forced Britain to revisit many of its diplomatic relationships, particularly

with nearby Spain.

The two countries share a long, tumultuous history that has culminated in outstanding

tension and unresolved disputes.

So, why are relations between Spain and the UK so complicated?

Well, the rivalry spans hundreds of years, before Spain was even a country, and before

England had absorbed Scotland and Ireland to become the UK.

Early on, the two butted heads over Portugal’s independence - once in the late 14th century,

when England helped the Portuguese army thwart an invasion from modern-day Spain, and again

200 years later, during the Anglo-Spanish War.

Throughout the next two centuries, England and Spain fought against each other in countless

battles in a number of wars.

In fact, the two countries didn’t officially become allies until 1834.

Today, much of Spain and the UK’s lasting hostility is centered around Gibraltar: a

tiny, 2-and-a-half-square-mile slice of land off the southern tip of Spain.

Gibraltar, also called “The Rock” is one of the UK’s last colonies.

It has been under their sovereignty since Spain surrendered the territory in 1713.

Spain has long since lobbied for its return, in part because it is physically attached

to the country, but also because it symbolizes a weak point in Spanish history.

Gibraltar has twice held referendums, and in both, voters overwhelmingly rejected Spanish

rule.

Although most of the territory’s roughly 30 thousand residents are of Spanish or Portuguese

descent, they are officially, and culturally, British.

Gibraltar has led to a number of flare-ups between Spain and the UK . In 2013, Spain’s

Navy arbitrarily patrolled Gibraltar’s waters despite Britain’s protests.

Tensions mounted again just months later, when Gibraltar built an artificial concrete

reef in its disputed waters with Spain, obstructing Spanish fishermen.

Spain retaliated by tightening border controls, and threatening to fine anyone trying to enter

from Gibraltar.

Spain and the UK were again forced to revisit their conflicting claims to Gibraltar in June

2016, when the UK voted to leave the European Union.

About 96 percent of Gibraltarians voted to stay in the bloc, as the territory relies

heavily on the EU for trade.

Once the Brexit vote came through, Spain used the opportunity to propose joint UK-Spanish

sovereignty of Gibraltar.

Gibraltar’s government, however, has insisted that such a proposal would never go through,

and is currently in negotiations to remain within the EU.

But despite this and other minor conflicts, relations between Spain and the UK are largely

positive.

Both are members of NATO and OECD, and both are parliamentary monarchies with many of

the same laws.

However pending the rollout of Brexit and the uncertain future of Gibraltar, we may

see their fragile relationship tested once again.