Image copyright Northern Rail Image caption Northern, which is also known as Arriva Rail North, was the main train operator in northern England

On Wednesday, troubled rail company Northern was brought under government control following concerns about its poor service and shaky finances.

The franchise will be stripped from operator Arriva Rail North from 1 March, and the government will step in as an "operator of last resort".

So what went wrong at Northern, and were the issues all its own fault? Moreover, will re-nationalisation fix the network's problems?

1. Delays and strikes

The Department for Transport (DfT) said Northern's poor service first came onto its radar after the botched rollout of a new timetable in May 2018.

The changes were designed to introduce more services and improve punctuality, but resulted in several weeks of chaos. Up to 300 services were cancelled each day.

Northern has been criticised for introducing the timetable without having enough certified drivers or the required infrastructure improvements being in place to deliver it.

But it points out that the DfT and others signed off on the timetable changes, despite having been warned that Northern would not have enough time to prepare for it.

Track manager Network Rail and the DfT were also rapped for showing a lack of "responsibility and accountability" during the rollout, according to regulator the Office of Rail and Road.

Image copyright Susan Ramsdale Image caption The botched timetable rollout led to weeks of chaos

Nevertheless, Northern's service did not fully recover. In the latest National Rail Passenger Survey, only 52% felt the network offered value for money, while punctuality and reliability was rated at 65%.

The operator also faced prolonged strikes in 2018 and 2019 over moves to change the role of guards on trains, causing further cancellations and delays.

It is important to remember these changes were dictated by the government, says rail industry journalist Tony Miles.

"The new operator is unlikely to find negotiations with staff any easier."

Image copyright Victoria Crossley Image caption Passengers dislike the network's old pacer trains

2. Infrastructure problems

The DfT said many of Northern's problems were due to "inadequate infrastructure" - although the operator says these issues were again beyond its control.

Firstly, Northern ordered more than 100 new trains from a Spanish company, but these have been up to a year late arriving. That meant it had to keep some of its old and unpopular trains running, including the hated Pacer trains.

Introduced in the early 1980s, Pacers - or "rail buses" - were only meant as a short-term alternative to proper trains and users complain they are noisy, cramped and poorly ventilated.

Delays in withdrawing them prompted northern leaders, including Greater Manchester Mayor Andy Burnham, to call on Northern to slash its fares. The operator says all the trains will have been retired by the end of February this year.

Northern also had to deal with an outdated track system in need of urgent upgrades. And delays to such projects - which are the fault of Network Rail and the government - have left it struggling with poor connections and bottlenecks.

Problem spots include Ordsall Chord - a stretch of line designed to increase capacity and reduce journey times into and through Manchester - which is not fully functioning.

There have also been delays to works between Blackpool and Manchester, as well as the electrification of lines across the North West.

This has compounded the poor service and made the introduction of new trains harder. "The government had promised it would upgrade a lot of the infrastructure to handle the extra trains, then cancelled most of the schemes. So the trains have been trying to run on a railway that is not able to handle them," says Mr Miles.

3. Shaky finances

The DfT says it ultimately re-nationalised the Northern franchise because it had become financially unviable.

In July 2019 it voiced concerns about declining passenger numbers on the network. That was despite an around 15% increase in services since the beginning of the franchise in 2016.

It also warned the government had been forced to increase its subsidy of Northern after the timetable fallout by £120m.

Northern counters that it did improve capacity on the lines and that passenger miles on the network were up in 2019.

Still, on 9 January this year, Transport Secretary Grant Shapps told the House of Commons the franchise would only be able to continue for a number of months, prompting him to consider re-nationalisation.

According to the government, Arriva has taken out no profit from the Northern franchise since it started in 2016.