THE opening of a major pharmeutical manufacturing and research site will bring best-selling author Terry Pratchett and the Japanese ambassador to Hatfield this morning.

Japanese firm Eisai, one of the world's leading drug companies, is opening its new European headquarters in the Hatfield Business Park next to T-Mobile, at 10.30am.

Sir Terry Pratchett, who has sold millions of books worlwide, particularly in the Discworld comic fantasy series, is supporting the formal opening because he suffers from Alzheimer's disease.

The company is pouring millions of pounds into searching for new medicines for conditions such as Alzheimer’s disease, Parkinson’s disease and epilepsy.