Complex sentence: By 1986, The The had released their second album "Infected", which reached number 14 in the UK Albums Chart and remained in the chart for 30 weeks, making it The The's most commercially successful album to date.
Split into simpler sentences: By 1986, The The had released their second album Infected. Despite only reaching number 14 in the UK Charts it stayed in the chart for 30 weeks making it The The's most commercially successful album to date.