Romanian crime group raided phone stores in South Shields, Seaham and Hartlepool
Members stormed stores in large groups and used "threats and intimidation" to walk off with over £150,000 of phones and computer tablets.
Stores from South Tyneside, Seaham, Hartlepool, County Durham and Northumberland came under attack.
Newcastle Crown Court heard many of the those involved in the criminal network have fled back to Romania.
But two men have admitted conspiracy to rob and are due to be sentenced later this month.
Ionatan Marin, of no fixed address but who was living in Harehills, Leeds, was carrying 13 mobile phones when he was arrested and was heavily involved in the raids.
The 19-year-old, who claimed he was just "lost in North Yorkshire" when the police swooped on him, is already serving a 54 month sentence for a shop robbery where a knife was brandished.
He had arrived in the UK in 2018, shortly before the offending started.
Ionatan Stefan, 18, of Bayswater Row, Harehills, Leeds, played a lesser role and took part in four of the phone shop raids.
Stefan, who now works at Sainsbury's, arrived in the UK in 2007 and was brought up in a Romani community in Leeds. He was married college student with two children at the time of the offences.
Prosecutor Jonathan Walker told the court the raids took place between May 2018 and June 2019 and said: "They used threats and intimidation to steal a very significant quantity of phones and electrical tablets.
"The offending had a significant impact on the businesses."
The court heard the first raids, in May 2018, were at O2 stores in Darlington, Blyth and Southampton.
In June 2018 a Carphone Warehouse in Darlington came under attack, a Vodaphone store in Lancaster in Lancashire followed by an O2 store in Leeds Trinity.
The following month stores in Durham, Leeds, Northumberland and Hartlepool were targeted.
Mr Walker said: "There were large groups entering the stores, there was aggression and then the phones were snatched."
In July 2018 O2 shops at South Shields, Seaham and Thornaby were raided.
A month later, a Carphone Warehouse in Hartlepool and other in Bury, Manchester, were raided, followed by O2 stores in Durham, Northampton and TheArnison Centre in County Durham.
On September 2018 the gang targeted O2 shops in Leeds, Berwick and Ellesmere Port in Cheshire.
Batley in West Yorkshire and an O2 shop in Galashiels in the borders were targeted in October 2018.
Then in December 2018 a Curry's store in Darlington and an O2 shop in Warrington were raided.
In January 2019 a Car Phone Warehouse an O2 shop and a TK Max in Warrington were all targeted followed by a Curry's shop in Middlesbrough the following month.
In February 2019 two O2 shops in Leeds came under attack, followed by an O2 store in Durham.
The last raid was in June 2019, at an O2 shop at Barrow-in-Furness in Cumbria.
Charles Blatchford, defending, said Marin's family are back in Romania and he hopes to return there as soon as possible.
Mr Blatchford said Marin was a youth at the time of the offences and added: "He was one of the younger participants in this offending. A number of the olderparticipants have fled the jurisdiction and avoided arrest."
Susannah Proctor, defending Stefan, said the raids were "smash and grab" offences and added: "They enter the shop, grab items that they can and leave."
Miss Proctor said Stefan, who was also a youth at the time, took part in four of the robberies and was paid a percentage of what was made at the raids he attended.
Miss Proctor said Stefan has been rehabilitated and now lives a law abiding family life.
Mr Recorder Neil Haythorne will sentence the men on September 29.