2016 was a year of long-expected farewells and the anticipation of arrivals for the Royal Navy.

Work has tirelessly been going into preparing HMS Queen Elizabeth for commission next year, whilst HMS Prince of Wales is still some time away.

Well-wishers said farewell to the beloved HMS Illustrious whilst the Sea Kings, which had stopped operations the previous year, made their final flight off into the sunset.

More: Royal Navy Sea Kings Fly Off Into The Sunset

Missions continued rescuing migrants crossing the Mediterranean, as did ongoing missions including patrolling the Falklands and the Antarctic.

Here's a round-up of some of the key events in the Royal Navy's 2016 calendar:

MP's Overwhelmingly Back Renewal Of Trident

There was fierce debate amongst MP's over whether to back the renewal of four new Successor submarines to carry Britain's nuclear deterrent.

Despite opposition from some members of the Labour Party, the Scottish National Party and one Conservative, MPs voted overwhelmingly in favour of keeping Trident.

The result was 472 votes in favour, which included 140 Labour votes to back renewing the deterrent against 117. 

Figures vary wildly over the cost of replacing Trident.

The government estimates that the Successor-class subs (to replace the Vanguard-class) will cost £31 billion for their entire 30-year lifetime (this includes adjustments for inflation over that time).
 
That works out to 6% of defence spending annually, at the current rate.
 
In addition, the government has recommended that a further £10 billion be set aside as a "contingency".

The Campaign for Nuclear Disarmament put's the overall cost over the 30 years at "at least £205 billion"

Reuters argued the cost to be £167bn, although this analysis was disputed by the MoD.  

More: Trident: In Numbers

Defence Secretary Michael Fallon said soon after the vote:
 

"MPs on all sides have voted by an overwhelming margin, to renew our nuclear deterrent - the ultimate guarantee of our national security."

Farewell Lusty

2016 saw HMS Illustrious' lengthy career come to an end, as she was towed out of Portsmouth harbour.

The 22,000-tonnne ship, affectionately known as ‘’Lusty’’, was formally decommissioned in August 2014 after 32 years of service and was sent for scrap in December.

More: 'Lusty' Heads For The Scrapheap 

Campaigns were launched to try and save HMS Illustrious, but none were able to stop her being sold for around £2 million.

She was formally launched in December 1978 by Princess Margaret.

The carrier was built by Swan Hunter shipbuilders on the River Tyne, and her entry into service was brought forward so she could assist in the Falklands war.

During the conflict, she relieved sister ship HMS Invincible in providing a floating airfield for aircraft unable to use the islands' damaged RAF base.

More: HMS Illustrious In Pictures

'Lusty' went on to support forces in Afghanistan and served in Bosnia and Sierra Leone.

She also helped to evacuate Britons during the war in Lebanon in 2006.

In 2013, Illustrious was involved in providing humanitarian aid and disaster relief after Typhoon Haiyan in the Philippines. 

More: A Brief History of HMS Illustrious

Migrant Rescue In The Mediterranean

In 2016 The Royal Navy continued its support of other European countries in tackling illegal people smuggling. 

The European Union Naval Force Mediterranean Operation Sophia is part of the European-wide response to the migration issue.

More: NATO Sails Into Migrant Crisis

2015 saw HMS Bulwark provide help to up to 5,000 people, after they were stranded in the waters between Libya and Italy.

More: HMS Bulwark: Migrant SOS

This year HMS Enterprise and HMS Diamond played key roles in addressing the crisis, something Leader of the Opposition Jeremy Corbyn referenced in his Christmas message.

The MoD also revealed that as part of Operation Sophia more than 100 boats intended for people smuggling had been destroyed, with HMS Diamond being sent to Libya in September for this purpose.

Figures released by the UN Refugee Agency in September showed that more than 300,000 refugees and migrants tried to cross the sea in 2016.

This is lower than the 520,000 registered sea arrivals during the first nine months of 2015.

The Navy Prepares For The Arrival Of New Carriers

HMS Queen Elizabeth and HMS Prince of Wales continued to be worked on this year, with the former nearing completion.

More: What We Can Expect From Britain’s New Carriers

Defence Secretary Sir Michael Fallon confirmed this year that the US will deploy F-35 fighter planes on board Queen Elizabeth.

The planes will be US Marine Corps F-35B jets, with UK planes expected to do the same on US vessels "in the fullness of time".

More: US To Fly F-35 From Royal Navy's HMS Queen Elizabeth

More: The Man Behind The Safe Arrival Of HMS Queen Elizabeth

It has been more than five years since the Royal Navy had an aircraft carrier.

It's hoped smart thinking and good design will allow Queen Elizabeth to operate with the comparatively low crew level of 650.

Queen Elizabeth could carry up to 72 aircraft at maximum capacity, though normally she would carry 12 to 24.

More: HMS Queen Elizabeth Shipshape And Almost Ready

However, work hasn't just been carried out on the aircraft carriers themselves.

£120 million is being spent on Portsmouth Naval base ahead of the carrier's arrival, which includes everything from upgrade electrics to bespoke gangways to get the crew on and off. 

In November Defence Secretary Sir Michael Fallon officially opened the new "Ark Royal" carrier training and operations building. 

More: Defence Secretary Gets Update On Royal Navy's New Aircraft Carrier