THE name Birtwistle runs like a thick thread through the historical tapestry of East Lancashire's now virtually-vanished cotton industry.

It is that of a dynasty whose chief at one time controlled 10,000 looms -- more than anyone else on Earth -- and who created what was said to be the the largest privately-owned textile manufacturing mill in Britain and probably also the world.

Reaching its peak in the early 1930s, the empire built by Blackburn-born William Birtwistle extended to 17 mills in his home town, Preston, Darwen, Great Harwood and Abbey Village, and in addition to that vast number of looms it also included 350,000 spindles.

Though it lasted 150 years from when its foundations were laid by his grandfather, nothing now remains of that giant industrial realm -- one that employed 9,000 people and enabled the head of the William Birtwistle Allied Mills Group to acquire huge mansions and own giant steam yachts.

One illuminating measure of the mill magnate's immense wealth is revealed in a new book* telling the history of the Birtwistle family. It was William's contribution to the "War Loan" scheme in 1918, the final year of the First World War. It was publicised by the visit of a tank called Egbert to Preston during the town's Savings Week -- when William Birtwistle's name topped the list of subscriptions with a donation of £116,000.

The following week, after the tank arrived in Blackburn for its fund-raising effort, when it was learned that the town's total was lagging behind Preston's, Birtwistle contributed another £100,000. In today's terms, those sums are equal to more than £4.8million.

It was money from an empire that was begun in Blackburn by his grandfather, William Birtwistle, a handloom weaver born at Read in 1808, who was a partner in the Stanley Street weaving and spinning mill that opened in 1851 in Blackburn and which came into his own control in 1863.

Inherited four years later by his son Micah, the mill became one of four that the new chief developed in the Daisyfield area, along with nearly 100 houses -- one of which he lived in himself -- that formed a cotton manufacturing estate. Micah made regular inspections of the houses to make sure their back yards were kept clean and tidy and even employed a man to sweep up horse droppings from the streets around the mills. But it was his second son, William, who was to really clean up as the creator of the mighty Allied Mills mills group that bore his name. Starting off in partnership with Richard Thompson, a former overlooker at the family's Stanley Street mill, on Micah's retirement in 1881, he added Woodfold Mill in Darwen and Nova Scotia Mill in Blackburn to their business. The partnership was dissolved in 1895, with William retaining the Stanley Street and Woodfold mills that were to be added to by more than a dozen other mills in the following three decades.

William's growing wealth saw him move from the family's Stanley Street terraced home to a large detached house at Salesbury and then in 1898 to Billinge Scar, the magnificent mansion on the outskirts of Blackburn that had been the home of brewer Daniel Thwaites, and where his brigadier-general son Arthur, successor at the helm of the business and creator of the John Hawkins nationwide chain of shops that sold Birtwistle textiles, built a massive greenhouse that was said to be the largest private one in Lancashire.

By then William, who died in 1936, had moved to an even grander mansion, Alston Hall, near Longridge, and presided over an estate that included 16 farms.

Billinge Scar, used a training centre for telephonists during the Second World War, was demolished in 1948 -- by when the Birtwistle group was about to embark on a £10million investment programme in a bid to combat erosion of their markets by the low-cost foreign imports that were eventually to decimate it and most of the UK textile industry.

By the late 1960s, pressure of competition forced Birtwistle's to close some of its spinning and weaving mills and 1971 the company sold out to a Manchester-based group, but contraction of the group continued through the 1970s and 1980s under its new ownership. The end came in 1992 when the last of the Birtwistle mills -- Waterfall Mill in Blackburn -- closed exactly 150 years on from when the family started Stanley Street Mill.

But the Birtwistle story is not just that of the rise and fall of biggest-of-them-all William Birtwistle. For, as the newly-published history relates, it is a family whose branches spread widely through cotton manufacture in Lancashire and influenced the development of dozens of other mills in the weaving belt between Preston and Padiham.

Its author, the late William "Billy" Birtwistle, who spent a lifetime compiling the family history, was head of WA Birtwistle (Damasks) Ltd, of Britannia Mill, in Didsbury Street, Blackburn, and was a leading figure in the 1960s Textile Action Group campaign for government aid for the industry.

He died suddenly in 1995 before his book could be printed, but it has now been published by his distant cousin, Miss Ellen Chambers. Copies are available from WH Smith and Bookland in Blackburn, the Kaydee Bookshop in Clitheroe and Oswaldtwistle Mills.

*Birtwistle -- A Family of East Lancashire Cotton Manufacturers, by WA Birtwistle (Ellen Chambers) £9.99.