Geography

The original Great Western Main Line linked London Paddington station with Temple Meads station in Bristol by way of Reading, Didcot, Swindon, Chippenham and Bath. This line was extended westwards through Exeter and Plymouth to reach Penzance, the most westerly railway station in England.

A line from Swindon ran through Gloucester to Cardiff, Swansea to west Wales. This route was later shortened by the opening of the Severn Tunnel. Another route ran northwards from Didcot to Oxford from where two different routes continued to Wolverhampton, one through Birmingham and the other through Worcester. Beyond Wolverhampton the line continued via Shrewsbury to Crewe, Chester and Birkenhead. Operating agreements with other companies also saw GWR trains run to Manchester.

South of the main line were routes from Didcot to Southampton via Newbury, and from Chippenham to Weymouth via Westbury.

There was a network of cross-country routes linking these lines and there were also many smaller branches to places such as Windsor, Basingstoke, Hereford and Salisbury. The Railways Act 1921 added many smaller companies within this area, notably the Cambrian Railways network in mid Wales and several railways in the Cardiff area.

Isambard Kingdom Brunel envisaged the GWR extending from London to New York and built the SS Great Western to carry the railway's passengers across the Atlantic ocean. Traffic soon switched to Liverpool but Great Western ships linked the United Kingdom with Ireland, the Channel Islands and France. The company owned a number of docks such as Fowey, Plymouth Millbay, Weymouth, and Cardiff.