As news of the death of Motorhead's iconic frontman Lemmy Kilmister makes its way around the world, the many musicians he influenced and counted as friends are expressing their grief on Twitter.

Lemmy died of cancer Monday (December 28), four days after his 70th birthday. According to the band's statement on Facebook, he had only learned of his diagnosis two days ago, and was at home playing a video game when he passed.

His death at the age of 70 ends one of the truly great rock n' roll lives. In the last few years of his life, his health issues forced Motorhead to cancel numerous shows. But he fought through it as best as he could and gave everything he had. An ultimate road dog, the band ended a European tour two weeks ago, which had its own share of problems. Shortly before they started, they learned of the death of former drummer Phil "Philthy Animal" Taylor. Then, the Paris terrorist attacks happened two days before they were scheduled to perform. Finally, an undisclosed illness to guitarist Phil Campbell saw them cancel three dates. Still, they were about to embark on another European tour on Jan. 23, 2016.

Heralded by a traditional onstage introduction of "We are Motorhead and we play rock n' roll," Motorhead's stripped-down, take-no-prisoners approach ultimately made Lemmy one of the few rockers who had credibility in punk, classic rock and metal circles.

For instance, Queen's Brian May – writing at brianmay.com – admits that "words don’t come easy, especially when you know Lemmy would have laughed at us all trying to say dignified things about him being a hero. Any time I attempted to say anything complimentary to Lemmy to his face, he would fix me with a kind of amused, contemptuous stare. But a kind of hero he certainly was. Unique in just about every way imaginable. He was a living mismatch of personality types. His music was roaring, abrasive, uncompromising, and his lyrics mostly deliberately gave no hint of sensitivity. Yet as a person he was a pacifist, a deep thinker, and a man who cared profoundly about his friends."

Meanwhile, ZZ Top's Billy Gibbons called Lemmy "a friend who upheld the rock ’n’ roll standard of the first order. The term 'iconic' applies and it would certainly be to Lemmy. His single mindedness and dedication have long been a source of constant intrigue and we’re confident Lemmy's enduring legacy will stand tall. Considering the ruckus he made during the life he led allows us to just leave with, 'Rock on, Lem."

Take a look below to see more of reactions from the world of rock ...

November 2015: Motorhead's Phil 'Philthy Animal' Taylor Dies

30 Historic Moments From Lemmy's Life