The main works were undertaken between 1972 and 1977.

A major renovation project was undertaken between 2009 and 2011.

More modern developments were undertaken between the 1970s to the 1990s.

The painting is believed to have been undertaken between 1503 and 1506.

More recently, restoration work was again undertaken between 1995 and 1996, when new stained glass windows were added.

Extensions to the southern training walls were undertaken between 1931 and 1933, with major additional works from 1946-1954.

The bulk of construction works was undertaken between 1926 and 1931.

The sinking of a new, No.4 shaft was undertaken between 1937 and 1939.

Such leases are usually undertaken between national or district governments and investors.

Phases 2 and 3 would be undertaken between 2015 and 2030.