The operation moved to Halifax (North of England - West Yorkshire) in the 1940s (some sources say 1930s, but the local papers say 40s), and as well as retaining their London factory they also opened one in Birkenhead (on the other side of the Mersey river from the city of Liverpool).

In 1963, the company was taken over by the immense Selincourt Group in a deal said to be worth more than £3 million. By this time it was trading as Harella International Fashions and achieved international standing in its own right as the second largest exporter in the UK fashion industry. In 1967 Harella closed its despatch unit at Brunswick House in Halifax and transferred it to their London headquarters. This left only the factory located in Halifax, based at Croftmyl in West Parade.

In 1968 when many other firms had been affected by economic squeezes, Harella's sales were expanding both in the UK and abroad. That year they opened outlets in six more countries and experienced their busiest season so far, with the Halifax factory in a constant flurry of activity, turning out women's garments for a worldwide market. This caused the firm to undergo a sweeping re-organisation in Halifax, introducing new machinary to improve work turnover and throughput, the factory's training school doubling in size, and more jobs - especially for school leavers. In the 60s their workforce averaged around 700 employees, which was immense for a British clothing firm at that time.

The textile industry regarded it as one of the most enterprising firms in a highly competitive field. Lew Harris himself was the one who initiated the trend for a wider range sizes for women's garments.

In 1979, Harella was taken over by the Barnsley-based firm S. R. Gent & Company Limited which kept on the 123 employees at Croftmyl. The factory finally closed in that year and the Croftmyl building went on to become occupied by the Halifax Chamber of Commerce.

From The Color of Black and White by Liz Lochhead

The moment she died, my mother’s dance dresses
turned from the colours they really were
to the colours I imagine them to be.
I can feel the weight of bumptoed silver shoes
swinging from their anklestraps as she swaggers
up the path towards her dad, light-headed
from airman’s kisses. Here, at what I’ll have to learn
to call my father’s house, yes every
ragbag scrap of duster prints her even more vivid
than an Ilford snapshot on some seafront
in a white cardigan and that exact frock.
Old lipstick. Liquid stockings.
Labels like Harella, Gor-ray, Berketex.
As I manhandle whole outfits into binbags for Oxfam
every mote in my eye is a utility mark
and this is useful:
the sadness of dispossessed dresses,
the decency of good coats roundshouldered
in the darkness of wardrobes,
the gravitas of lapels,
the invisible dandeers of skin fizzing off from them
like all that life that will not neatly end.